Risk Management Series

Primer 

to Design Safe School Projects in Case of Terrorist Attacks

December 2003

FEMA

FEMA 428

RISK MANAGEMENT SERIES

Primer to 

Design Safe School Projects 

in Case of Terrorist Attacks

PROVIDING PROTECTION TO PEOPLE AND BUILDINGS

FEMA 428 / December 2003

Federal Emergency Management Agency

www.fema.gov

T he creation of the Department of Homeland Security 

(DHS) is one of the most significant transformations 

in the Federal Government in decades, establishing a 

department whose first priority is to protect the nation against 

terrorist attack. Within the DHS, the Directorate of Emergency 

Preparedness and Response (EP&R) is focused on ensuring that 

our nation is prepared for catastrophes, including both natural 

disasters and terrorist assaults.

This Primer for Protection of Schools Against Terrorist Attacks 

provides guidance to protect students, faculty, staff, and their 

school buildings from terrorist attacks. It also provides guidance 

to the building science community of architects and engineers 

working for local institutions on school projects. 

This document is intended for use by schools who feel that they 

are at risk to terrorist attacks. It provides necessary guidance to 

those who desire to increase the performance of their school 

and related infrastructure. Not all schools are at risk of terrorist 

attacks. The decision-makers in each school district should use 

current and available threat information from the proper sources 

to make this determination. The use of experts to apply the methodologies contained in this document is encouraged. 

This primer references several sources for additional information, 

including publications completed by other government agencies. 

The reader is encouraged to obtain additional guidance.

This document was prepared by the Building Sciences and Technology Branch of the Mitigation Division, part of EP&R. DHS 

would like to thank the following agencies for their contribution 

and input to this publication:

❍ General Services Administration

❍ Naval Facilities Engineering Service Center

❍ Naval Facilities Command (NAVFAC) Criteria Office
❍ USACE Protective Design Center

❍ Department of Veterans Affairs

❍ Centers for Disease Control and Prevention/National 

Institute for Occupational Safety and Health

❍ Department of Justice, Office of Domestic Preparedness 

(DHS - Border and Transportation Security)

❍ United States Air Force - Civil Engineer Support Agency
FOREWORD AND ACKNOWLEDGMENTS

FOREWORD AND ACKNOWLEDGMENTS i

BACKGROUND

T he purpose of this primer is to provide the design community and school administrators with the basic principles and techniques to make a school that is safe from terrorist 

attacks and at the same time is functional, aesthetically pleasing, 

and meets the needs of the students, staff, administration, and 

general public. Protecting a school building and grounds from 

physical attack is a significant challenge because the ability to 

design, construct, renovate, operate, and maintain the facility is 

spread across numerous building users, infrastructure systems, 

and many building design codes. 

There is a strong interest 

in the United States (U.S.) 

in ensuring the safety of 

students, faculty, and staff 

in our schools. Schools are 

integral parts of their communities. On any given 

weekday, nearly 53 million young people aged 

5 to 17 attend more than 

117,000 public and private 

schools where 6 million 

adults work as teachers or 

staff (counting students, 

faculty, and staff, this constitutes more than one-fifth of the U.S. 

population). Additionally, schools are resources for their communities. Many schools are used as shelters, command centers, or 

meeting places in times of crisis. Schools are also used widely for 

polling and voting functions. In some communities, schools are 

places of health care delivery.

Schools may or may not be the targets of terrorism, but they are 

certain to be affected by terrorism, whether directly or indirectly. 

An American high school
ii FOREWORD AND ACKNOWLEDGMENTS 

On September 11, 2001, four elementary schools and three high 

schools located within 6 blocks of the World Trade Center were 

just beginning classes when the first plane hit the north tower. 

Thousands of children were exposed to the dust clouds from the 

collapsing buildings. Even those children not in the immediate 

vicinity experienced a great deal of anxiety. Children in at least 

three states (New York, New Jersey, and Connecticut) had parents 

working in or around the World Trade Center that day. In the 

Washington, DC, area, schools faced similar situations after the 

Pentagon was attacked.1

Many Americans feel that schools should be the safest place our 

children can be, perhaps at times even safer than the homes in 

which they live. Security is not a standalone capability; it is a critical design consideration that should be constantly reviewed and 

scrutinized from the design phase through construction or rehabilitation and onto building use.

The focus of this primer will be on the threats posed by potential 

physical attacks on a school by terrorists. Attacking schools and 

school children could be a highly emotional and high profile 

event. At the time of publication of this primer, there have been 

no direct terrorist threats against a school known to the public; 

however, schools could be indirectly threatened by collateral 

damage from a terrorist attack directed at nearby facilities. Protecting a school against terrorist attack is a challenging task. A 

school may have considerable vulnerabilities, because of its well 

defined periods of use, designated access points, storage of sensitive personal information, minimal security forces, and numerous 

avenues of penetration and escape for attackers.

This primer should be used in conjunction with the Federal 

Emergency Management Agency (FEMA) 426, Reference Manual to 

Mitigate Potential Terrorist Attacks Against Buildings, and FEMA 427, 

Primer for Design of Commercial Buildings to Mitigate Terrorist Attacks.

1 National Advisory Committee on Children and Terrorism (NACCT)
FOREWORD AND ACKNOWLEDGMENTS iii

SCOPE

This primer presents an approach to protecting schools at risk from 

terrorist attacks. The information presented is intended primarily 

for architects and engineers, or school administrators with a technical background. This publication is designed to meet the needs of 

all schools, including those with serious security concerns. Because 

security concerns of individual schools vary greatly, some users with 

modest security concerns may feel beleaguered by the amount of 

information and technical approach presented. They should feel 

free to select the methods and measures that best meet their individual situations while gaining a general appreciation of security 

concerns and risk management.

Several design philosophies and techniques have been incorporated into this primer, including the Department of Defense 

(DoD) Minimum Antiterrorism Standards, the Army and Air 

Force Security Engineering Manual, the General Services Administration (GSA) Public Building Standards, the Department of 

Veterans Affairs (VA) Building Vulnerability Assessment Checklist, 

and the Centers for Disease Control and Prevention (CDC)/

National Institute for Occupational Safety and Health (NIOSH) 

Guidelines for Airborne Contaminants.

ORGANIZATION AND CONTENT OF THE 

PRIMER

This publication contains many how-to aspects based upon current information contained in FEMA, Department of Commerce 

(DOC), DoD (including Army, Navy, and Air Force), Department 

of Justice (DOJ), GSA, VA, CDC/NIOSH, and other publications. 

It is intended to provide an understanding of the current methodologies for assessing threat/hazard, vulnerability, and risk, and the 

design considerations needed to improve protection of new and 

existing buildings and the people occupying them. As needed, this 

primer should be supplemented with more extensive technical resources, as well as the use of experts when necessary.
iv FOREWORD AND ACKNOWLEDGMENTS 

❍	 Chapter 1 presents a methodology for architects, engineers, 

and school administrators to analyze the safety of students, 

teachers, and staff for vulnerabilities to various terrorist 

threats. The methodology presented will assist schools in 

performing risk management by helping them to identify the 

best and most cost-effective terrorism mitigation measures for 

their unique security needs.

❍	 Chapters 2 and 3 discuss site and layout, and building design 

guidance and safety plans, respectively, and mitigation 

measures or comprehensive architectural and engineering 

design considerations to provide an acceptable level of 

protection. Specifically, Chapter 2 discusses comprehensive 

architectural and engineering design considerations for the 

school site, from the property line to the school building. Chapter 

3 presents design considerations for the building envelope.

❍	 Chapter 4 is a brief discussion of explosive blast theory. 

Chapter 5 presents chemical, biological, and radiological 

(CBR) measures that can be taken to mitigate school 

vulnerabilities and reduce associated risk for these terrorist 

tactics or technological hazards.

❍	 Chapter 6 is a standalone description of the concept of safe 

rooms within schools that will resist CBR and blast threats 

intended to provide school board members and decisionmakers with the basic components of a protective system.

❍	 Appendices A, B, and C contain acronyms, general definitions, 

and chemical and biological agent characteristics, respectively. 

Appendix B is an extensive glossary with terminology used in 

the report.

❍	 Appendices D and E present a comprehensive bibliography 

of publications (including information for obtaining the 

publications), and the associations and organizations 

capturing the building security guidance needed by the 

building sciences community (including web sites), respectively. 
FOREWORD AND ACKNOWLEDGMENTS v

❍	 Appendix F contains the Building Vulnerability Assessment 

Checklist.

ACKNOWLEDGEMENTS

Principal Authors:

Wesley Lyon, UTD, Inc.

Robert Smilowitz, Weidlinger Associates, Inc.

Pax Williams, Battelle Memorial Institute

Contributors:

Michael Kaminskas, UTD, Inc.

Eric Letvin, Greenhorne & O’Mara, Inc.

Christopher Arnold, Building Systems Development, Inc.

Michael Chipley, UTD, Inc.

Shawn Fenn, FEMA

Randall Hoffman, UTD, Inc.

Damian Kolbay, UTD, Inc.

Eve Hinman, ATC/Hinman Consulting Engineers, Inc.

Robert Burns, UTD, Inc.

Curt Betts, U.S. Army Engineer District, Omaha

Connie Deshpande, Department of Education

Bill Modzeleski, Department of Education

Randy Haslam, Jordan, Utah, School District

Deb Daly, Greenhorne & O’Mara, Inc.

Wanda Rizer, Greenhorne & O’Mara, Inc.

Julie Liptak, Greenhorne & O’Mara, Inc.

Bob Pendley, Greenhorne & O’Mara, Inc.
vi FOREWORD AND ACKNOWLEDGMENTS

Project Manager:

Milagros Kennett, FEMA

Building Sciences Technology Branch

Mitigation Division

This primer will be revised periodically and EP&R welcomes 

comments and feedback to improve future editions. Please send 

comments and feedback via e-mail to 

riskmanagementseriespubs@dhs.gov
TABLE OF CONTENTS

TABLE OF CONTENTS vii

FOREWORD AND ACKNOWLEDGMENTS ...................................................... i

CHAPTER 1 – ASSET VALUE, THREAT/HAZARD, 

VULNERABILITY, AND RISK.................................................................... 1-1

1.1 Asset Value Assessment ......................................................... 1-2

1.1.1 Identifying School Core Functions........................... 1-4

1.1.2 Identifying School Infrastructure ............................. 1-4

1.1.3 Quantifying Asset Value............................................. 1-5

1.2 Threat/Hazard Assessment................................................... 1-7

1.2.1 Threat Identification ................................................. 1-9

1.2.2 Threat Definition..................................................... 1-13

1.2.3 Threat Assessment Products ................................... 1-15

1.2.4 Design Basis Threat ................................................. 1-18

1.3 Vulnerability Assessment ..................................................... 1-20

1.4 Risk Assessment.................................................................... 1-23

1.5 The Risk Management Process ........................................... 1-28

CHAPTER 2 – SITE AND LAYOUT DESIGN GUIDANCE ............................... 2-1

2.1 Land Use Considerations ..................................................... 2-2

2.2 Site Planning ......................................................................... 2-4

2.2.1 Site Design.................................................................. 2-4

2.2.2 Layout and Form........................................................ 2-4

2.2.3 Vehicular and Pedestrian Circulation ...................... 2-9

2.2.4 Landscape and Urban Design................................. 2-10

2.3 Stand-off Distance ................................................................ 2-14

2.4 Controlled Access Zones .................................................... 2-16
viii TABLE OF CONTENTS 

2.5 Entry Control and Vehicular Access................................... 2-20

2.6 Signage.................................................................................. 2-21

2.7 Parking.................................................................................. 2-22

2.8 Loading Docks and Service Access..................................... 2-24

2.9 Physical Security Lighting.................................................... 2-25

2.10 Site Utilities.......................................................................... 2-26

2.11 Summary of Site Mitigation Measures ............................... 2-28

2.12 Crime Prevention Through 

Environmental Design (CPTED)........................................ 2-33

CHAPTER 3 – BUILDING DESIGN GUIDANCE AND SAFETY PLANS................ 3-1

3.1 Architectural........................................................................... 3-2

3.2 Building Structural and Non-structural Systems.................. 3-5

3.3 Building Envelope................................................................ 3-10

3.3.1 Building Exterior ..................................................... 3-10

3.3.2 Exterior Wall Design................................................ 3-10

3.3.3 Window Design ........................................................ 3-12

3.3.4 Doors......................................................................... 3-17

3.3.5 Roofs ......................................................................... 3-18

3.4 Mechanical Systems ............................................................. 3-18

3.5 Electrical Systems................................................................. 3-24

3.6 Fire Protection Systems........................................................ 3-25

3.7 Communications Systems.................................................... 3-26

3.8 Physical Security Systems..................................................... 3-27

3.9 Summary of Building Envelope Mitigation 

Measures............................................................................... 3-29
TABLE OF CONTENTS ix

3.10 Recommendations Based on the 

Homeland Security Advisory System .................................. 3-32

3.11 School Safety Emergency Management Plan..................... 3-33

3.12 Emergency Plans and Training ........................................... 3-36

CHAPTER 4 – EXPLOSIVE BLAST............................................................. 4-1

4.1 Blast Effects............................................................................. 4-1

4.1.1 Building Damage ....................................................... 4-3

4.1.2 Casualties and Injuries............................................... 4-5

4.1.3 Levels of Protection ................................................... 4-5

4.2 Stand-off Distance and the Effects of Blast ........................ 4-10

CHAPTER 5 – CHEMICAL, BIOLOGICAL, AND RADIOLOGICAL MEASURES ..... 5-1

5.1 Evacuation .............................................................................. 5-2

5.2 Sheltering in Place ................................................................. 5-3

5.3 Personal Protective Equipment ............................................ 5-6

5.4 Air Filtration and Pressurization........................................... 5-8

5.5 Exhausting and Purging ........................................................ 5-8

5.6 CBR Detection........................................................................ 5-9

5.7 Indications of CBR Contamination .................................... 5-11

CHAPTER 6 – SAFE ROOMS WITHIN SCHOOLS......................................... 6-1

6.1 Types of CBR Hazards............................................................ 6-2

6.1.1 Toxic Industrial Chemicals........................................ 6-2

6.1.2 Incapacitating and Tear-producing Agents.............. 6-3

6.1.3 Biological Agents........................................................ 6-3

6.1.4 Radiological Agents ................................................... 6-4

6.2 Most Likely Delivery Methods for CBR Agents.................... 6-4
x TABLE OF CONTENTS 

6.2.1 Internal Release ......................................................... 6-5

6.2.2 External Proximate Release ...................................... 6-5

6.2.3 Remote Release.......................................................... 6-5

6.2.4 Remote Release with Forewarning ........................... 6-6

6.3 Vulnerability to Remote CBR Release .................................. 6-6

6.4 Vulnerability to Remote CBR Release with 

Forewarning.......................................................................... 6-10

6.5 Vulnerability to Internal CBR Release................................ 6-11

6.6 Vulnerability to External Proximate CBR Release............. 6-11

6.7 Recommendations for CBR Protection............................ 6-16

6.8 Safe Rooms in Response to the Domestic

Explosive Threat .................................................................. 6-16

6.9 Locating Safe Rooms to Mitigate Threats........................ 6-20

6.10 Fragment Mitigating Upgrades......................................... 6-24

6.11 Structural Upgrades........................................................... 6-30

APPENDIX A – ACRONYMS

APPENDIX B – GENERAL GLOSSARY

APPENDIX C – CBR AGENT CHARACTERISTICS

APPENDIX D – BIBLIOGRAPHY

APPENDIX E – ASSOCIATIONS AND ORGANIZATIONS

APPENDIX F – BUILDING VULNERABILITY ASSESSMENT CHECKLIST
TABLE OF CONTENTS xi

TABLES

Chapter 1

Table 1-1 Asset Value Scale......................................................... 1-6

Table 1-2 Nominal High School People and 

Asset Value Assessment ............................................. 1-7

Table 1-3 Homeland Security Threat Conditions .................. 1-10

Table 1-4 Event Profiles for Terrorism and 

Technological Hazards............................................. 1-15

Table 1-5 Threat Rating Scale ................................................. 1-16

Table 1-6 Nominal High School Threat Assessment.............. 1-17

Table 1-7 Vulnerability Rating Scale........................................ 1-21

Table 1-8 Nominal High School Vulnerability 

Assessment ................................................................ 1-22

Table 1-9 Risk Rating System ................................................... 1-24

Table 1-10 Risk Color Value System........................................... 1-25

Table 1-11 Nominal School Risk Assessment Matrix................ 1-26

Chapter 2

Table 2-1 Correlation of Mitigation Measures 

to Threats.................................................................. 2-30

Chapter 3

Table 3-1 Glazing Protection Levels Based 

on Fragment Impact Locations............................... 3-13

Table 3-2 Correlation of GSA Glazing Performance 

Conditions and DoD Levels of Protection 

for New Buildings..................................................... 3-14

Table 3-3 Safety/Security Recommendations......................... 3-32
xii TABLE OF CONTENTS 

Chapter 4

Table 4-1 DoD Minimum Antiterrorism (AT) 

Standards for New Buildings..................................... 4-6

Table 4-2 Correlation of DoD Level of Protection 

to Incident Pressure ................................................... 4-6

Table 4-3 Damage Approximations......................................... 4-13

Chapter 5

Table 5-1 Indicators of a Possible Chemical Incident............ 5-13

Table 5-2 Indicators of a Possible Biological Incident ........... 5-15

Table 5-3 Indicators of a Possible Radiological Incident....... 5-15

Chapter 6

Table 6-1 Pressures Exerted on a School Building 

Face by Wind............................................................. 6-13

FIGURES

Chapter 1

Figure 1-1 The assessment process model.................................. 1-2

Figure 1-2 Typical building design and 

construction process ................................................ 1-19

Figure 1-3 Risk management choices ....................................... 1-19

Chapter 2

Figure 2-1 Non-redundant critical functions

collocated near loading dock .................................... 2-6

Figure 2-2 Clustering to enhance surveillance 

opportunities while minimizing views into 

buildings...................................................................... 2-7

Figure 2-3 Blocking of sight lines.............................................. 2-13
TABLE OF CONTENTS xiii

Figure 2-4 Improper building siting and view relationships... 2-13

Figure 2-5 Clear zone with unobstructed views........................ 2-14

Figure 2-6 Concept of stand-off distance.................................. 2-15

Figure 2-7 Exclusive and non-exclusive zones.......................... 2-17

Figure 2-8 Sample bollard applications.................................... 2-18

Chapter 3

Figure 3-1 Re-entrant corners in a floor plan ............................ 3-3

Figure 3-2 Glazed areas oriented perpendicularly 

away from streets ........................................................ 3-4

Figure 3-3 Offset doors through the foyer ................................. 3-5

Figure 3-4 Side view of a test structure illustrating 

performance conditions of Table 3-2...................... 3-13

Figure 3-5 An unprotected window after a large 

explosion................................................................... 3-15

Figure 3-6 Sacrificial roof........................................................... 3-18

Figure 3-7 Example of protecting outdoor air intakes............ 3-20

Figure 3-8 Another example of protecting air intakes............ 3-21

Figure 3-9 Example of elevated air intake................................ 3-21

Figure 3-10 Example of enclosing an existing 

vulnerable air intake ................................................ 3-22

Figure 3-11 Considerations for the design of a new 

security system .......................................................... 3-28

Figure 3-12 Physical security devices........................................... 3-29

Chapter 4

Figure 4-1 Blast pressure effects on a structure.......................... 4-4

Figure 4-2 Explosives environments - blast range to effects...... 4-8
xiv TABLE OF CONTENTS

Figure 4-3 Blast analysis of a high school for a 

typical car bomb detonated in the 

school’s parking lot .................................................... 4-9

Figure 4-4 Blast analysis of a high school for a 

typical large truck bomb detonated in 

the school’s parking lot.............................................. 4-9

Figure 4-5 Relationship of cost to stand-off distance............... 4-10

Figure 4-6 Incident overpressure measured in pounds 

per square inch, as a function of stand-off 

distance and net explosive weight 

(pounds-TNT) .......................................................... 4-13

Chapter 5

Figure 5-1 Example of chemical dispersion ............................... 5-3

Figure 5-2 Universal-fit escape hood........................................... 5-7

Figure 5-3 An IMS chemical detector designed for 

installation in HVAC systems................................... 5-10

Figure 5-4 Placards associated with chemical incidents .......... 5-14

Figure 5-5 Placards associated with biological incidents......... 5-15

Figure 5-6 Placards associated with radiological incidents...... 5-16
ASSET VALUE, THREAT/HAZARD, VULNERABILITY, AND RISK 1

ASSET VALUE, THREAT/HAZARD, VULNERABILITY, AND RISK 1-1

T his chapter presents methodologies for architects, engineers, school administrators, and state and local officials working in the building sciences field to identify the most 

effective mitigation measures to achieve a desired level of protection against terrorist attacks. These methodologies will help 

designers define asset value and evaluate vulnerability assessment 

information for the purpose of integrating threat/hazard into a 

design basis. Architects and engineers will be able to identify the 

best and most cost-effective terrorism mitigation measures for 

each building's unique security needs. Mitigation measures are 

conceived by the design professional and are best incorporated 

into the building architecture, building systems, and operational 

parameters, with consideration for life-cycle costs. The methodologies described in this chapter can be used for new buildings 

during the design process, as well as for existing buildings undergoing renovation. A key tool in the assessment process is provided 

for the designer in the last section of this chapter, the Building 

Vulnerability Assessment Checklist.

In order to create a safe school environment, many factors must 

be considered. Figure 1-1 depicts the assessment process presented 

in this primer to help each school identify the best and most costeffective terrorism mitigation measures for its own unique security 

needs. Section 1.1 identifies the value of a school’s assets (e.g., 

people, buildings, equipment, and processes) that need to be 

protected, recognizing that students, faculty, and staff will always 

be a school’s most vital asset requiring protection. Section 1.2 describes how to conduct a threat/hazard assessment to identify and 

define the threats and hazards that could cause harm to a school. 

Section 1.3 discusses how to perform a vulnerability assessment to 

identify school weaknesses that might be exploited by a terrorist 

or aggressor. Combining the results of the asset value, threat, and 

vulnerability assessments in Sections 1.1 through 1.3, the next step 

in the assessment process is to perform a risk assessment (Section 

1.4) to determine to what degree a school’s assets are vulnerable 
1-2 ASSET VALUE, THREAT/HAZARD, VULNERABILITY, AND RISK 

to attack. The final step of the process is presented in Section 1.5, 

where risk management decisions are discussed to prioritize and 

decide on the best and most cost-effective terrorism mitigation 

measures to implement to achieve the desired level of protection. 

A school assessment is best performed by engineering and security professionals who are experts in risk management, building 

design, blast effects, and chemical, biological, and radiological 

(CBR) attacks, as well as the latest antiterrorism (AT) security 

measures. If it is not feasible to hire professionals, members of the 

design community and/or school administrators can perform an 

assessment using the methodology presented in this primer. Some 

schools may choose to take a hybrid approach, hiring specialists or 

consultants to help perform individual portions of the assessment 

process.

1.1 ASSET VALUE ASSESSMENT

This section will describe how to perform an asset value assessment (the first step of the assessment process), to identify people 

Figure 1-1 The assessment process model
ASSET VALUE, THREAT/HAZARD, VULNERABILITY, AND RISK 1-3

and the asset value. To facilitate identifying people and the value 

of a school’s assets, it is useful to conduct interviews of the people 

who are most familiar with them. Inputs from school administrators, teachers, nurses, custodial staff, cafeteria staff, and students, 

as well as any others who can help identify the most valuable assets should be sought. In order to conduct productive interviews, 

a list of areas to be covered should be generated and prioritized 

prior to the actual interviews. Thorough planning and research 

to generate relevant questions will aid the process and yield better 

results.

An asset is a resource of value requiring protection.1 An asset can 

be tangible (e.g., students, faculty, staff, school buildings, facilities, 

equipment, activities, operations, and information) or intangible 

(e.g., processes or a school’s reputation). In order to achieve the 

greatest risk reduction at the least cost, identifying and prioritizing 

a school’s critical assets is a vital first step in the process to identify 

the best mitigation measures to improve its level of protection 

prior to a terrorist attack. Recognizing that people are a school’s 

most critical asset, the process described below will help identify 

and prioritize school infrastructure where people are most at risk 

and require protection.

Identifying a school’s critical assets is accomplished in a two-step 

process:

Step 1: Define and understand the school’s core functions and 

processes

Step 2: Identify school infrastructure

❍ Critical components/assets

❍ Critical information systems and data

❍ Life safety systems and safe haven areas

❍ Security systems

1 Appendix B is a glossary of assessment and security terminology. Appendix C contains chemical 

and biological agent characteristics.
1-4 ASSET VALUE, THREAT/HAZARD, VULNERABILITY, AND RISK 

1.1.1 Identifying School Core Functions

The initial step of an asset value assessment is the determination 

of core functions and processes necessary for the school to continue to operate or provide services after an attack. The reason for 

identifying core functions/processes is to focus the design team 

and school administrators on what a school does, how it does it, 

and how various threats can affect the school. This provides more 

discussion and results in a better understanding of asset value. 

Factors that should be considered include:

❍ What are the school’s primary services or outputs?

❍ What critical activities take place at the school?

❍ Who are the school’s occupants or visitors?

❍ What inputs from external organizations are required for a 

school’s success?

1.1.2 Identifying School Infrastructure

After the core functions and processes are identified, an evaluation of school infrastructure is the next step. To help identify 

and value rank infrastructure, the following should be considered, keeping in mind that the most vital asset for every school is 

its people:

❍ Identify how many people may be injured or killed during a 

terrorist attack that directly affects the infrastructure.

❍ Identify what happens to school functions, services, or student 

satisfaction if a specific asset is lost or degraded. (Can primary 

services continue?)

❍ Determine the impact on other organizational assets if the 

component is lost or can not function.

❍ Determine if critical or sensitive information is stored or 

handled at the school.

❍ Determine if backups exist for the school’s assets.

❍ Determine the availability of replacements.
ASSET VALUE, THREAT/HAZARD, VULNERABILITY, AND RISK 1-5

❍ Determine the potential for injuries or deaths from any 

catastrophic event at the school’s assets.

❍ Identify any critical faculty, staff, or administration whose 

loss would degrade, or seriously complicate the safety of 

students, faculty, and staff during an emergency. [Consider 

first responders or the personnel responsible for shelter 

operations at a school that is a designated shelter for natural 

hazards.]

❍ Determine if the school’s assets can be replaced and identify 

replacement costs if the school building is lost.

❍ Identify the locations of key equipment.

❍ Determine the locations of personnel work areas and systems 

within a school.

❍ Identify the locations of any personnel operating “outside” a 

school’s controlled areas.

❍ Determine, in detail, the physical locations of critical support 

architectures:

• Communications and information technology (IT - the flow 

of critical information)

• Utilities (e.g., facility power, water, air conditioning, etc.)

• Lines of communication that provide access to external 

resources and provide movement of students and faculty 

(e.g., road, rail, air transportation)

❍ Determine the location, availability, and readiness condition 

of emergency response assets, and the state of training of 

school staff in their use.

1.1.3 Quantifying Asset Value

After a list of a school’s assets or resources of value requiring 

protection have been identified, they should be assigned a value. 

Asset value is the degree of debilitating impact that would be 

caused by the incapacity or destruction of the school’s assets. 
1-6 ASSET VALUE, THREAT/HAZARD, VULNERABILITY, AND RISK 

There are many scales that can be used, each with advantages 

and disadvantages. Because some people are used to working 

with linguistic scales, although many engineers and designers 

prefer numerical systems, this publication will use a combination 

of a seven-level linguistic scale and a ten-point numerical scale as 

shown in Table 1-1. Obviously, the key asset for every school is its 

people (e.g., students, faculty, and staff). They will always be assigned the highest asset value as in the example below.

Table 1-1: Asset Value Scale

Asset Value

Very High 10

High 8-9

Medium High 7

Medium 5-6

Medium Low 4

Low 2-3

Very Low 1

Very High – Loss or damage of the school’s assets would have 

exceptionally grave consequences, such as extensive loss of life, 

widespread severe injuries, or total loss of primary services and 

core functions and processes. 

High – Loss or damage of the school’s assets would have grave 

consequences, such as loss of life, severe injuries, loss of primary 

services, or major loss of core functions and processes for an extended period of time.

Medium High – Loss or damage of the school’s assets would have 

serious consequences, such as serious injuries, or impairment of 

core functions and processes for an extended period of time.

Medium – Loss or damage of the school’s assets would have moderate to serious consequences, such as injuries, or impairment of 

core functions and processes.
ASSET VALUE, THREAT/HAZARD, VULNERABILITY, AND RISK 1-7

Medium Low – Loss or damage of the school’s assets would have 

moderate consequences, such as minor injuries, or minor impairment of core functions and processes.

Low – Loss or damage of the school’s assets would have minor 

consequences or impact, such as a slight impact on core functions 

and processes for a short period of time.

Very Low – Loss or damage of the school’s assets would have negligible consequences or impact.

Asset Value Example. A nominal list of assets for a typical high 

school with assigned value is presented in Table 1-2. Please note 

that this is a nominal example; each school should tailor its list 

to its own unique situation. In Section 1.4, the results of the asset 

value assessment will be combined with the results of a threat assessment (Section 1.2) and a vulnerability assessment (Section 1. 3) 

to determine total risk.

1.2 THREAT/HAZARD ASSESSMENT

After identifying asset value, the next step in the assessment process is to conduct a threat/hazard assessment wherein the threats 

or hazards are identified, defined, and quantified. Within the 

Department of Defense (DoD), intelligence community, and law 

enforcement, the term “threat” is typically used to describe the 

design criteria for terrorism or manmade disasters. Within the 

Federal Emergency Management Agency (FEMA) and other civil 

agencies, the term “hazard” is used in several different contexts. 

“Natural hazard” typically refers to a natural event such as an 

earthquake, a flood, or a wind disaster. “Manmade hazards” are 

“technological hazards” and “terrorism.” These are distinct from 

natural hazards primarily in that they originate from human activity. Furthermore, “technological hazards” are generally assumed 

to be accidental, and their consequences are considered unintended. For the sake of simplicity, this primer will use the terms 

“threat” and “hazard” when referring to terrorism and manmade 

disasters, respectively.
1-8 ASSET VALUE, THREAT/HAZARD, VULNERABILITY, AND RISK 

Table 1-2: Nominal High School Asset Value Assessment

Asset Value Numeric Value

Students Very High 10

Faculty Very High 10

Staff Very High 10

Designated Shelter (safe haven) Very High 10

Main School Building High 9

Teaching Functions High 9

IT/Communications Systems High 8

Utilities Associated with Shelter Medium High 7

Utility Systems (gas, electrical, sewer/water) Medium High 7

Nurses Station Medium High 7

School/Student Records Medium High 7

Transportation (buses and parking) Medium High 7

Security Equipment (metal detectors, badge equipment) Medium High 7

Administrative Functions Medium 5

Temporary Classrooms (trailers) Medium Low 4

Food Service (cafeteria/kitchen) Medium Low 4

Library Low 3

Custodial Functions Low 3

Science Laboratories Low 3

Vocational Equipment (shops) Low 3

Indoor Sports Facilities Low 2

Outdoor Sports Facilities Very Low 1

For terrorism, the threat is from aggressors (those people with 

intent to do harm) that are known to exist, have the capability 

for hostile actions, and have expressed intentions for using hostile actions. They may seek publicity for their cause or political 

gain through their actions to injure or kill people, and destroy or 

damage facilities, property, equipment, or resources. 
ASSET VALUE, THREAT/HAZARD, VULNERABILITY, AND RISK 1-9

Aggressor tools can be forced entry tools, vehicles, or surveillance (visual/audio). Their weapons can be incendiary devices; 

small arms (rifles and handguns); stand-off military-style weapons 

(rocket propelled grenades or mortars); explosive devices; and 

CBR agents. Their tactics run the gamut: moving vehicle bombs; 

stationary vehicle bombs; exterior attacks (thrown objects like 

rocks, Molotov cocktails, hand grenades, or hand-placed bombs); 

stand-off weapons attacks (small arms, military or improvised 

direct and indirect fire weapons); covert entries (gaining entry 

by false credentials or circumventing security with or without 

weapons); mail bombs (delivered to individuals or institutions); 

airborne contamination (CBR agents used to contaminate the air, 

water, or food supply to a school); and waterborne contamination 

(CBR agents injected into the water supply of a school facility).

A threat assessment is a continual process of compiling and 

examining all available information concerning potential 

threats and manmade hazards. It can be broken down into two 

processes (1) defining threats and (2) identifying threat event 

profiles and tactics. 

1.2.1 Threat Identification

The beginning point for security design is to define threats (hazards) and tactics that may be employed. From a physical attack 

viewpoint, schools maybe susceptible to attack by a number of different threats and tactics especially in areas of high risk. Schools 

are typically site constrained, have well defined traffic control and 

entry points, and operate on standard schedules. Designers and 

school administrators need to evaluate attack objectives, threat 

event profiles, and the effects or impact of the attack on the 

school and its occupants. It should also be noted that weapons 

and tactics change faster than the construction of schools. Table 

1-3 provides a broad spectrum of manmade threats/hazards to 

consider and can be used as a tool in the threat assessment process. An extensive list of potential chemical and biological agents 

that can be used in terrorist attacks is provided in Appendix C. 

Blast range effects are indicated throughout Chapter 4.
1-10 ASSET VALUE, THREAT/HAZARD, VULNERABILITY, AND RISK 

Table 1-3: Event Profiles for Terrorism and Technological Hazards* 

Threat/Hazard Application Mode Duration Extent of Effects; 

Static/Dynamic

Mitigating and 

Exacerbating Conditions

Nuclear Device Detonation of 

nuclear device 

underground, at the 

surface, in the air, 

or at high altitude. 

Light/heat flash and 

blast/shock wave 

last for seconds; 

nuclear radiation 

and fallout hazards 

can persist for years.

Electromagnetic 

pulse from a highaltitude detonation 

lasts for seconds 

and affects only 

unprotected 

electronic systems. 

Initial light, heat, 

and blast effects of a 

subsurface, ground, or 

air burst are static and 

are determined by the 

device’s characteristics 

and employment; 

fallout of radioactive 

contaminants may be 

dynamic, depending 

on meteorological 

conditions. 

Harmful effects of 

radiation can be reduced 

by minimizing the time 

of exposure. Light, heat, 

and blast energy decrease 

logarithmically as a function 

of distance from seat of 

blast. Terrain, forestation, 

structures, etc., can provide 

shielding by absorbing and/

or deflecting radiation and 

radioactive contaminants. 

Biological Agent

- Anthrax

- Botulism

- Bru cellosis

- Plague

- Smallpox

- Tularemia

- Viral 

Hemorrhagic 

Fevers

- Toxins 

(Botulinum,

Ricin, 

Staphylococcal 

Enterotoxin B, 

T-2 Mycotoxins)

Liquid or solid 

contaminants can 

be dispersed using 

sprayers/aerosol 

generators or by 

point or line sources 

such as munitions, 

covert deposits, and 

moving sprayers. 

May be directed 

at food or water 

supplies.

Biological agents 

may pose viable 

threats for hours to 

years, depending on 

the agent and the 

conditions in which it 

exists.

Depending on the 

agent used and the 

effectiveness with 

which it is deployed, 

contamination can be 

spread via wind and 

water. Infection can 

be spread via human 

or animal vectors. 

Altitude of release above 

ground can affect dispersion; 

sunlight is destructive to 

many bacteria and viruses; 

light to moderate winds 

will disperse agents, but 

higher winds can break up 

aerosol clouds; the micrometeorological effects of 

buildings and terrain can 

influence aerosolization and 

travel of agents. 
ASSET VALUE, THREAT/HAZARD, VULNERABILITY, AND RISK 1-11

Table 1-3: Event Profiles for Terrorism and Technological Hazards* (continued)

Threat/Hazard Application Mode Duration Extent of Effects; 

Static/Dynamic

Mitigating and 

Exacerbating Conditions

Chemical Agent

- Blister

- Blood

- Choking/Lung/ 

Pulmonary

- Incapacitating

- Nerve

- Riot Control/Tear 

Gas

- Vomiting

Liquid/aerosol 

contaminants can 

be dispersed using 

sprayers or other 

aerosol generators; 

liquids vaporizing 

from puddles/ 

containers; or 

munitions.

Chemical agents 

may pose viable 

threats for hours to 

weeks, depending 

on the agent and the 

conditions in which it 

exists. 

Contamination can 

be carried out of the 

initial target area 

by persons, vehicles, 

water, and wind. 

Chemicals may be 

corrosive or otherwise 

damaging over time if 

not remediated. 

Air temperature can affect 

evaporation of aerosols. 

Ground temperature affects 

evaporation of liquids. Humidity 

can enlarge aerosol particles, 

reducing the inhalation hazard. 

Precipitation can dilute and 

disperse agents, but can spread 

contamination. Wind can 

disperse vapors, but also cause 

target area to be dynamic. The 

micro-meteorological effects 

of buildings and terrain can 

alter travel and duration of 

agents. Shielding in the form of 

sheltering in place may protect 

students, faculty, staff, and 

property from harmful effects. 

Radiological Agent

- Alpha

- Beta

- Gamma

Radioactive 

contaminants can 

be dispersed using 

sprayers/aerosol 

generators, or by 

point or line sources 

such as munitions, 

covert deposits, and 

moving sprayers. 

Contaminants may 

remain hazardous 

for seconds to 

years, depending on 

material used. 

Initial effects will be 

localized to site of 

attack; depending 

on meteorological 

conditions, subsequent 

behavior of radioactive 

contaminants may be 

dynamic. 

Duration of exposure, 

distance from source of 

radiation, and the amount 

of shielding between source 

and target determine 

exposure to radiation. 

Improvised 

Explosive Device 

(Bomb)

- Stationary 

Vehicle

- Moving Vehicle

- Mail

- Supply

- Thrown

- Placed

- Personnel 

Detonation of 

explosive device on 

or near target; via 

person, vehicle, or 

projectile. 

Instantaneous; 

additional secondary 

devices may be 

used, lengthening 

the time duration of 

the threat/hazard 

until the attack site 

is determined to be 

clear. 

Extent of damage 

is determined by 

type and quantity 

of explosive. Effects 

generally static 

other than cascading 

consequences, 

incremental structural 

failure, etc. 

Blast energy at a given 

stand-off is inversely 

proportional to the cube 

of the distance from the 

device; thus, each additional 

increment of stand-off 

provides progressively more 

protection. Exacerbating 

conditions include ease of 

access to target; lack of 

barriers/shielding; poor 

construction; and ease of 

concealment of device.
1-12 ASSET VALUE, THREAT/HAZARD, VULNERABILITY, AND RISK 

Arson/ Incendiary 

Attack

Initiation of fire 

or explosion on 

or near target 

via direct contact 

or remotely via 

projectile. 

Generally minutes to 

hours. 

Extent of damage 

is determined by 

type and quantity 

of device/accelerant 

and materials present 

at or near target. 

Effects generally static 

other than cascading 

consequences, 

incremental structural 

failure, etc. 

Mitigation factors include builtin fire detection and protection 

systems and fire-resistive 

construction techniques. 

Inadequate security can allow 

easy access to target, easy 

concealment of an incendiary 

device, and undetected initiation 

of a fire. Non-compliance 

with fire and building codes 

as well as failure to maintain 

existing fire protection systems 

can substantially increase the 

effectiveness of a fire weapon.

Table 1-3: Event Profiles for Terrorism and Technological Hazards* (continued)

Threat/Hazard Application Mode Duration Extent of Effects; 

Static/Dynamic

Mitigating and 

Exacerbating Conditions

Hazardous Material 

Release

(fixed facility or 

transportation)

- Toxic Industrial 

Chemicals 

and Materials 

(Organic vapors: 

cyclohexane; Acid 

gases: cyanogens, 

chlorine, hydrogen 

sulfide; Base 

gases: ammonia; 

Special cases: 

phosgene, 

formaldehyde)

Solid, liquid, 

and/or gaseous 

contaminants may 

be released from 

fixed or mobile 

containers.

Hours to days. Chemicals may be 

corrosive or otherwise 

damaging over time. 

Explosion and/or fire 

may be subsequent. 

Contamination may 

be carried out of 

the incident area by 

persons, vehicles, 

water, and wind.

As with chemical weapons, 

weather conditions will directly 

affect how the hazard develops. 

The micro-meteorological 

effects of buildings and terrain 

can alter travel and duration 

of agents. Shielding in the 

form of sheltering in place can 

protect students, faculty, staff, 

and property from harmful 

effects. Non-compliance with 

fire and building codes as well 

as failure to maintain existing 

fire protection and containment 

features can substantially 

increase the damage from a 

hazardous materials release. 

Armed Attack

- Ballistics (small 

arms)

- Stand-off Weapons 

(rocket propelled 

grenades, mortars) 

Tactical assault or 

sniper attacks from 

a remote location.

Generally minutes 

to days

Varies, based upon the 

perpetrators’ intent 

and capabilities.

Inadequate security can 

allow easy access to target, 

easy concealment of 

weapons, and undetected 

initiation of an attack.
ASSET VALUE, THREAT/HAZARD, VULNERABILITY, AND RISK 1-13

Table 1-3: Event Profiles for Terrorism and Technological Hazards* (continued)

Threat/Hazard Application Mode Duration Extent of Effects; 

Static/Dynamic

Mitigating and 

Exacerbating Conditions

Cyberterrorism Electronic attack 

using one computer 

system against 

another.

Minutes to days. Generally no direct 

effects on built 

environment. 

Inadequate security can 

facilitate access to critical 

computer systems, allowing 

them to be used to conduct 

attacks.

Unauthorized 

Entry

- Forced

- Covert

Use of hand or 

power tools, 

weapons, or 

explosives to 

create a man-sized 

opening or operate 

an assembly 

(such as a locked 

door), or use false 

credentials to 

enter a building or 

simple covert entry.

Minutes to hours, 

depending upon the 

intent.

If goal is to steal 

or destroy physical 

assets or compromise 

information, the initial 

effects are quick, but 

damage may be long 

lasting. If intent is 

to disrupt operations 

or take hostages, the 

effects may last for a 

long time, especially if 

injury or death occurs.

Standard physical security 

building design should be 

the minimum mitigation 

measure. For more critical 

assets, additional measures, 

like closed circuit television 

(CCTV) or traffic flow that 

channels visitors past access 

control, aids in detection of 

this hazard.

 *ADAPTED FROM: FEMA 386-7, INTEGRATING HUMAN-CAUSED HAZARDS INTO MITIGATION PLANNING, SEPTEMBER 2002.

1.2.2 Threat Definition

A threat (hazard) is any indication, circumstance, or event with 

the potential to cause loss of, or damage to an asset. It is important to understand who are the people with the intent to cause 

harm; or who, by process, materials, or proximity, can cause indirect harm to a school building. With the goal of reducing the 

potential risk of a school building, the design team and school 

administration should seek threat assessment information from 

local law enforcement, the local office of the Federal Bureau of 

Investigation (FBI), State Health Departments, the Department 

of Homeland Security (DHS), and the Homeland Security Offices 

(HSOs) at the state level. In many areas of the country, there are 

threat coordinating committees that facilitate the sharing of information. Local fire departments and hazardous materials (HazMat) 
1-14 ASSET VALUE, THREAT/HAZARD, VULNERABILITY, AND RISK 

units will frequently understand the threat of technological hazards due to hazardous materials on school grounds as well as those 

in surrounding industries that could cause a collateral threat to 

schools. In many jurisdictions, the HazMat unit is part of the fire 

department. 

After information on potential aggressors is gathered, it should be 

analyzed. A common method to evaluate terrorist threats uses five 

factors: existence, capability, history, intention, and targeting.

Existence addresses the questions: Who is hostile to our school 

building or community of concern? Are they present or thought 

to be present? Are they able to enter the country or are they 

readily identifiable in a local community upon arrival?

Capability addresses the questions: What weapons have been used 

in carrying out past attacks? Do the aggressors need to bring 

them into the area or are they available locally?

History addresses the questions: What has the potential threat element done in the past and how many times? When was the most 

recent incident and where, and against what target? What tactics 

did they use? Are they supported by another group or individuals? 

How did they acquire their demonstrated capability?

Intention addresses the questions: What does the potential threat 

element or aggressor hope to achieve? How do we know this (e.g., 

published in books or news accounts, speeches, letters to the 

editor, informant)?

Targeting addresses the questions: Do we know if an aggressor 

(we may not know which specific one) is performing surveillance on our school, nearby facilities, or facilities that have much 

in common with our school? Is this information current and 

credible, and indicative of preparations for terrorist operations 

(manmade hazards)?
ASSET VALUE, THREAT/HAZARD, VULNERABILITY, AND RISK 1-15

Table 1-4: Homeland Security Threat Conditions

Threat Level Threat Analysis Factors

Existence Capability History Intentions Targeting

Severe (Red) ● ● ● ● ●

High (Orange) ● ● ● ● ❑

Elevated (Yellow) ● ● ● ❑

Guarded (Blue) ● ● ❑

Low (Green) ● ❑

● Factor must be present ❑	Factor may or may not be present

Please note the DHS does not use these threat analysis factors to determine threat level. 

SOURCE: COMMONWEALTH OF KENTUCKY OFFICE OF HOMELAND SECURITY.

The threat/hazard analysis for a school can range from a general 

threat/hazard scenario shared by all members of a community to 

a very detailed examination of specific groups, individuals, and 

tactics that must be repelled or defended against by means of 

school design. The Homeland Security Advisory System has five 

threat levels that provide a general indication of risk of terrorist 

attack. In Table 1-4, the five factors commonly used to evaluate 

terrorist threats have been layered onto the Homeland Security 

Advisory levels. It illustrates threat levels and provides a representation of the likelihood of a terrorist attack. If the anticipated 

threat or projected character/use of the facility warrant, a detailed 

threat analysis should be developed in coordination with local 

law enforcement, intelligence, and civil authorities in order to 

more quantitatively determine the vulnerability or risk. All schools 

should identify actions to be taken for each threat level. A table with 

specific recommendations for schools based on the Homeland Security Threat Advisory Level is presented in Chapter 3 (Table 3-3).

1.2.3 Threat Assessment Products

A threat assessment is a continual process of compiling and examining all available information concerning potential threats 

and manmade hazards. The product of a threat assessment is a list 
1-16 ASSET VALUE, THREAT/HAZARD, VULNERABILITY, AND RISK 

of threats and hazards with a threat rating assigned. The threat 

rating is a subjective judgment based on existence, capability, history, intention, and targeting. Often, information is sketchy and 

analysts must rely more on the judgment of experts, statistical probability, and occasionally assumptions to help quantify and qualify 

the threat (all assumptions should be documented). The same 

combination of linguistic scale and numerical scale used in the asset 

value assessment (Table 1-1) can be used for the threat assessment as 

presented in Table 1-5. Assessing terrorist threats is much more difficult than assessing the risk from natural hazards such as earthquakes, 

floods, and winds. Historical data form the basis of threat and locality 

indicates vulnerability to a great extent in regard to natural hazards. 

For terrorist threats, the likelihood of occurrence is less defined and 

the associated vulnerabilities have many considerations that impact 

making good risk management decisions. 

Table 1-5: Threat Rating Scale

Threat Rating

Very High 10

High 8-9

Medium High 7

Medium 5-6

Medium Low 4

Low 2-3

Very Low 1

Very High – Known aggressors or hazards, highly capable of 

causing loss of, or damage to the school exist. One or more 

vulnerabilities are present. The aggressors are known or highly 

suspected of having intent to exploit the school's assets and are 

known or highly suspected of performing surveillance on a facility.

High – Known aggressors or hazards, capable of causing loss of, 

or damage to the school exist. One or more vulnerabilities are 

present and the aggressors are known or reasonably suspected of 

having intent to exploit the school’s assets.
ASSET VALUE, THREAT/HAZARD, VULNERABILITY, AND RISK 1-17

Medium High – Known aggressors or hazards, capable of causing 

loss of, or damage to the school exist. One or more vulnerabilities 

are present and the aggressor is suspected of having intent to exploit the school’s assets. 

Medium – Known aggressors or hazards that may be capable 

of causing loss of, or damage to the school exist. One or more 

vulnerabilities may be present; however, the aggressors are not believed to have intent to exploit the school’s assets.

Medium Low – Known aggressors or hazards that may be capable 

of causing loss of or damage to the school exist. Aggressors have 

no intent to exploit the school’s assets.

Low – Few or no aggressors or hazards exist. Their capability of 

causing damage to the school’s assets is doubtful.

Very Low – No aggressors or hazards exist.

Threat Assessment Example. A nominal list of threats/hazards 

with assigned threat rating is presented in Table 1-6. Please note 

that this is a nominal example; each school should tailor its list to 

its own unique situation. 

Table 1-6: Nominal High School Threat Assessment

Threat/Hazard Threat Rating Numeric Threat Rating

Stationary vehicle bomb Low 2

Attack with small arms Medium Low 4

Hydrogen sulfide “stink bomb” Medium 5

Forced entry at night to damage school property Medium High 7

Electronic attack to destroy or alter school academic 

records Medium High 7
1-18 ASSET VALUE, THREAT/HAZARD, VULNERABILITY, AND RISK 

1.2.4 Design Basis Threat

Traditionally, the building regulatory system has addressed natural disaster mitigation (hurricane, tornado, flood, earthquake, 

windstorm, and snow storm) through prescriptive building codes 

supported by well-established and accepted reference standards, 

regulations, inspection, and assessment techniques. Some manmade risks (e.g., HazMat storage) and specific societal goals 

(energy conservation and life safety) have also been similarly 

addressed. However, the building regulation system has not yet 

fully addressed most manmade hazards or terrorist threats.

Soon after September 11, 2001, the New York City Building 

Department initiated an effort to analyze the building code in 

relation to terrorist threats. The task force issued a report recommending code changes based on the attack on the World 

Trade Center. The National Fire Protection Association (NFPA) 

has a committee on premises security and security system installation standards. These advancements may some day result in 

the building regulatory system developing prescriptive building 

codes to mitigate security threats.

In the absence of such regulations, identifying design basis 

threats (e.g., threat tactics, weapons, tools, or explosives against 

which a building must be protected) should be considered as 

part of a school’s threat assessment to facilitate the work of designers during new construction or rehabilitation of an existing 

school building. The DoD, General Services Administration 

(GSA), and Department of State (DOS) all have established processes to identify design basis threats for their facilities.

The typical building design and construction process is sequential, 

progressing from identifying building use and design goals through 

actual construction. This process is illustrated in Figure 1-2.
ASSET VALUE, THREAT/HAZARD, VULNERABILITY, AND RISK 1-19

In every school design and renovation project, there are ultimately 

three choices of how to address the risk posed by terrorism:

1. Do nothing and accept the risk

2. Perform a risk assessment and manage the risk by installing reasonable mitigation measures to achieve a 

desired level of protection

3. Harden the building against all threats to achieve the 

least amount of risk

Figure 1-3 is a graphical representation of the three choices. Since 

September 11, 2001, terrorism has become a dominant concern. 

Life, safety, and security issues should be a design goal from the 

beginning for all schools. 

Figure 1-2 Typical building design and construction process

Figure 1-3 Risk management choices
1-20 ASSET VALUE, THREAT/HAZARD, VULNERABILITY, AND RISK 

1.3 VULNERABILITY ASSESSMENT

A vulnerability assessment evaluates vulnerability, or any weaknesses 

that can be exploited by an aggressor, of critical assets across a broad 

range of identified threats and provides a basis for determining mitigation measures for protection of people and critical assets.

The Building Vulnerability Assessment Checklist provided in Appendix F is based on the checklist developed by the Department 

of Veterans Affairs (VA) and compiles many best practices based 

upon technologies and scientific research to consider during the 

design of a new building or an assessment of an existing school 

building. It allows a consistent security evaluation of designs at 

various levels. The checklist can be used as a screening tool for 

an initial vulnerability assessment or be used by subject matter 

experts for a comprehensive vulnerability assessment of existing 

school buildings.

The assessment of any vulnerability of a school building should 

be done within the context of the defined threats and the value 

of the school’s assets. That is, each element of the school building 

should be analyzed for vulnerabilities to each threat and a vulnerability rating should be assigned. The same combination of 

linguistic scale and numerical scale used in the asset value and 

threat assessments (Tables 1-1 and 1-5) can also be used for the 

vulnerability assessment as presented in Table 1-7. It should be 

noted that a vulnerability assessment may change the value rating 

of assets due to the identification of critical nodes or some other 

factor that makes the school’s assets more valuable.
ASSET VALUE, THREAT/HAZARD, VULNERABILITY, AND RISK 1-21

Table 1-7: Vulnerability Rating Scale

Vulnerability Rating

Very High 10

High 8-9

Medium High 7

Medium 5-6

Medium Low 4

Low 2-3

Very Low 1

Very High – One or more major weaknesses have been identified 

that make the school’s assets extremely susceptible to an aggressor 

or hazard.

High – One or more significant weaknesses have been identified that 

make the school’s assets highly susceptible to an aggressor or hazard.

Medium High – An important weakness has been identified that 

makes the school’s assets very susceptible to an aggressor or hazard.

Medium – A weakness has been identified that makes the school’s 

assets fairly susceptible to an aggressor or hazard.

Medium Low – A weakness has been identified that makes the 

school’s assets somewhat susceptible to an aggressor or hazard.

Low – A minor weakness has been identified that slightly increases 

the susceptibility of the school’s assets to an aggressor or hazard.

Very Low – No weaknesses exist.

Vulnerability Assessment Example. To create the vulnerability 

assessment of a school, a site vulnerability assessment should be 

performed using the checklist in Appendix F. The results of the 

vulnerability assessment are then analyzed in conjunction with the 

results of the asset value and threat assessments developed earlier. 

Each asset/threat pair is then assigned a vulnerability rating as 

shown in Table 1-8 and forms the basis for identifying measures 

to mitigate threat vulnerability and improve protection of the 

building and its occupants. Please note that this is a nominal example; each school should tailor its list to its own unique situation. 
1-22 ASSET VALUE, THREAT/HAZARD, VULNERABILITY, AND RISK 

THREAT/HAZARD

Terrorist 

Act

Armed 

Attack

Unauthorized 

Entry

Low Level 

CBR Attack

Cyberterrorism

Stationary Vehicle 

Bomb

Attack by Small 

Arms

Forced Entry at 

Night to Damage 

School Property

Hydrogen 

Sulfide “Stink 

Bomb”

Electronic Attack 

to Destroy or 

Alter School 

Academic 

Records

Vulnerability

Rating

Vulnerability

Rating

Vulnerability

Rating

Vulnerability

Rating

Vulnerability

Rating

Students VH 10 H 9 VL 1 MH 7 VL 1

Faculty VH 10 H 9 VL 1 MH 7 ML 4

Staff VH 10 H 9 ML 4 MH 7 ML 4

Designated Shelter (safe haven) H 9 L 3 ML 4 L 3 VL 1

Main School Building VH 10 ML 4 M 5 L 3 VL 1

Teaching Functions VH 10 VH 10 ML 4 H 9 L 3

IT/Communications Systems VH 10 M 5 MH 7 L 2 MH 7

Utilities Associated with Shelter H 8 ML 4 L 2 VL 1 VL 1

Utility Systems (gas, electrical, 

sewer/water)

MH 7 ML 4 M 5 L 2 VL 1

Nurses Station H 9 H 8 M 6 L 3 VL 1

School/Student Records H 9 L 3 M 6 L 2 MH 7

Transportation (buses and parking) VH 10 H 9 M 6 L 3 VL 1

Security Equipment (metal 

detectors, badge equipment)

H 9 MH 7 M 6 L 2 VL 1

Administrative Functions VH 10 H 8 M 6 MH 7 M 5

Temporary Classrooms (trailers) VH 10 VH 10 MH 7 ML 4 VL 1

Food Service (cafeteria/kitchen) VH 10 H 8 M 5 MH 7 VL 1

Library VH 10 VH 10 MH 7 MH 7 ML 4

Custodial Functions VH 10 ML 4 M 6 ML 4 VL 1

Science Laboratories VH 10 M 5 H 8 L 3 VL 1

Vocational Equipment (shops) VH 10 ML 4 H 8 L 3 VL 1

Indoor Sports Facilities VH 10 ML 4 H 8 M 6 VL 1

Outdoor Sports Facilities M 5 L 2 MH 7 L 2 VL 1

VH = Very High; H = High; MH = Medium High; M = Medium; ML = Medium Low; L = Low; VL = Very Low

Table 1-8: Nominal High School Vulnerability Assessment

ASSET
ASSET VALUE, THREAT/HAZARD, VULNERABILITY, AND RISK 1-23

1.4 RISK ASSESSMENT

Risk is the potential for a loss of or damage to an asset. It is 

measured based upon the value of the asset in relation to the 

threats and vulnerabilities associated with it. Risk is based on the 

likelihood or probability of the hazard occurring and the consequences of the occurrence. A risk assessment analyzes the threat 

(probability of occurrence), and asset value and vulnerabilities 

(consequences of the occurrence) to ascertain the level of risk 

for each asset against each applicable threat/hazard. Thus, a 

very high likelihood of occurrence with very small consequences 

may require simple, low cost mitigation measures, but a very 

low likelihood of occurence with very grave consequences may 

require more costly and complex mitigation measures. The risk 

assessment provides engineers, architects, and school administrators with a relative risk profile that defines which assets are at the 

greatest risk against specific threats. Chapters 2 and 3 explore 

mitigation measures to reduce the vulnerability and risk for valuable assets with a high risk.

There are numerous methodologies and techniques for conducting a risk assessment. One approach is to assemble the results 

of the asset value assessment, threat assessment, and vulnerability 

assessment, and determine a numeric value of risk for each asset 

and threat/hazard pair in accordance with the following formula:

Risk = Asset Value x Threat Rating x Vulnerability Rating

The completed matrix provides a quantitative value for risk that 

can be converted into a linguistic value as shown in Table 1-9. The 

following rating system can be used for assessing the risk of schools.
1-24 ASSET VALUE, THREAT/HAZARD, VULNERABILITY, AND RISK 

Table 1-9: Risk Rating System

Risk Risk Rating

≥ 261 Very High

201 - 260 High

141 - 200 Medium High

101 - 140 Medium

61 - 100 Medium Low

31 - 60 Low

1 - 30 Very Low

Very High – The potential for loss or damage of the school’s assets 

is so great as to expect exceptionally grave consequences, such as 

extensive loss of life, widespread severe injuries, or total loss of primary services, and core functions and processes. 

High – The potential for loss or damage of the school’s assets is so 

great as to expect grave consequences, such as loss of life, severe 

injuries, loss of primary services, or major loss of core functions 

and processes for an extended period of time.

Medium High – The potential for loss or damage of the school’s 

assets is such as to expect serious consequences (e.g., as serious 

injuries, or impairment of core functions and processes for an extended period of time).

Medium – The potential for loss or damage of the school’s assets 

is such as to expect serious consequences (e.g., injuries, or impairment of core functions and processes).

Medium Low – The potential for loss or damage of the school’s assets is such as to expect only moderate consequences (e.g., minor 

injuries, or minor impairment of core functions and processes).

Low – The potential for loss or damage of the school’s assets is 

such as to expect only minor consequences or impact (e.g., a slight 

impact on core functions and processes for a short period of time).

Very Low – The potential for loss or damage of the school’s assets is 

so low that there would only be negligible consequences or impact.
ASSET VALUE, THREAT/HAZARD, VULNERABILITY, AND RISK 1-25

Because of the large amount of information in a risk assessment 

matrix, it is useful to assign a color code (red, yellow, or green) 

based on the total numeric value of risk determined based on the 

scale in Table 1-10. 

Table 1-10: Risk Color Value System

Low Risk Medium Risk High Risk

Risk Factors Total 1-60 61-175 ≥ 176

As a minimum, mitigation measures to reduce risk and create 

an acceptable level of protection should be considered for those 

critical assets determined to be at highest risk. 

Risk Assessment Example. A nominal risk assessment is presented 

in Table 1-11 based on the asset value, threat, and vulnerability 

assessment examples presented earlier. As mentioned previously, 

each school should tailor its list to its own unique situation. 
1-26 ASSET VALUE, THREAT/HAZARD, VULNERABILITY, AND RISK 

Table 1-11: Nominal High School Risk Assessment Matrix

Threat/Hazard

Terrorist 

Act

Armed 

Attack

Unauthorized 

Entry

Low Level 

CBR Attack

Cyberterrorism

Stationary Vehicle 

Bomb

Attack by Small 

Arms

Forced Entry at 

Night to Damage 

School Property

Hydrogen 

Sulfide “Stink 

Bomb”

Electronic Attack 

to Destroy or 

Alter School 

Academic 

Records

Students/Faculty/Staff 200 360 50 490 140

Asset Value Rating 10 10 10 10 10

Threat Rating 2 4 5 7 7

Vulnerability Rating 10 9 1 7 2

Designated Shelter (safe haven) 180 120 200 210 70

Asset Value Rating 10 10 10 10 10

Threat Rating 2 4 5 7 7

Vulnerability Rating 9 3 4 3 1

Main School Building 180 144 225 189 63

Asset Value Rating 9 9 9 9 9

Threat Rating 2 4 5 7 7

Vulnerability Rating 10 4 5 3 1

Teaching Functions 60 120 60 189 63

Asset Value Rating 3 3 3 3 3

Threat Rating 2 4 5 7 7

Vulnerability Rating 10 10 4 9 3

IT/Communications Systems 160 160 280 112 392

Asset Value Rating 8 8 8 8 8

Threat Rating 2 4 5 7 7

Vulnerability Rating 10 5 7 2 7

Utilities Associated with Shelter 112 112 70 49 49

Asset Value Rating 7 7 7 7 7

Threat Rating 2 4 5 7 7

Vulnerability Rating 8 4 2 1 1

Utility Systems (gas, electrical, 

sewer/water) 98 112 175 98 49

Asset Value Rating 7 7 7 7 7

Threat Rating 2 4 5 7 7

Vulnerability Rating 7 4 5 2 1

Nurses Station 126 224 210 147 49

Asset Value Rating 7 7 7 7 7

Threat Rating 2 4 5 7 7

Vulnerability Rating 9 8 6 3 1
ASSET VALUE, THREAT/HAZARD, VULNERABILITY, AND RISK 1-27

Threat/Hazard

Terrorist 

Act

Armed 

Attack

Unauthorized 

Entry

Low Level 

CBR Attack

Cyberterrorism

Stationary Vehicle 

Bomb

Attack by Small 

Arms

Forced Entry at 

Night to Damage 

School Property

Hydrogen 

Sulfide “Stink 

Bomb”

Electronic Attack 

to Destroy or 

Alter School 

Academic 

Records

School/Student Records 126 84 210 98 343

Asset Value Rating 7 7 7 7 7

Threat Rating 2 4 5 7 7

Vulnerability Rating 9 3 6 2 7

Transportation (buses and parking) 140 252 210 147 49

Asset Value Rating 7 7 7 7 7

Threat Rating 2 4 5 7 7

Vulnerability Rating 10 9 6 3 1

Security Equipment (metal 

detectors, badge equipment) 126 196 210 98 49

Asset Value Rating 7 7 7 7 7

Threat Rating 2 4 5 7 7

Vulnerability Rating 9 7 6 2 1

Administrative Functions 100 160 150 245 175

Asset Value Rating 5 5 5 5 5

Threat Rating 2 4 5 7 7

Vulnerability Rating 10 8 6 7 5

Temporary Classrooms (trailers) 80 160 140 112 28

Asset Value Rating 4 4 4 4 4

Threat Rating 2 4 5 7 7

Vulnerability Rating 10 10 7 4 1

Food Service (cafeteria/kitchen) 80 128 100 196 28

Asset Value Rating 4 4 4 4 4

Threat Rating 2 4 5 7 7

Vulnerability Rating 10 8 5 7 1

Library 60 120 105 147 84

Asset Value Rating 3 3 3 3 3

Threat Rating 2 4 5 7 7

Vulnerability Rating 10 10 7 7 4

Custodial Functions 60 48 90 84 21

Asset Value Rating 3 3 3 3 3

Threat Rating 2 4 5 7 7

Vulnerability Rating 10 4 6 4 1

Table 1-11: Nominal High School Risk Assessment Matrix (continued)
1-28 ASSET VALUE, THREAT/HAZARD, VULNERABILITY, AND RISK 

Table 1-11: Nominal High School Risk Assessment Matrix (continued)

Threat/Hazard

Terrorist 

Act

Armed 

Attack

Unauthorized 

Entry

Low Level 

CBR Attack

Cyberterrorism

Stationary Vehicle 

Bomb

Attack by Small 

Arms

Forced Entry at 

Night to Damage 

School Property

Hydrogen 

Sulfide “Stink 

Bomb”

Electronic Attack 

to Destroy or 

Alter School 

Academic 

Records

Science Laboratories 60 60 120 63 21

Asset Value Rating 3 3 3 3 3

Threat Rating 2 4 5 7 7

Vulnerability Rating 10 5 8 3 1

Vocational Equipment (shops) 60 48 120 63 21

Asset Value Rating 3 3 3 3 3

Threat Rating 2 4 5 7 7

Vulnerability Rating 10 4 8 3 1

1.5 THE RISK MANAGEMENT PROCESS

Risk management is the process of selecting and implementing 

mitigation measures to achieve an acceptable level of risk at an 

acceptable cost. Because it is cost-prohibitive to protect against 

the entire range of possible threats, it is important to develop a 

realistic prioritization of mitigation measures. When considering 

mitigation measures, the following factors should be considered: 

❍ Results of the risk assessment, including asset value and asset 

vulnerabilities

❍ Costs of the mitigation measures

Indoor Sports Facilities 40 32 80 84 14

Asset Value Rating 2 2 2 2 2

Threat Rating 2 4 5 7 7

Vulnerability Rating 10 4 8 6 1

Outdoor Sports Facilities 10 8 35 14 7

Asset Value Rating 1 1 1 1 1

Threat Rating 2 4 5 7 7

Vulnerability Rating 5 2 7 2 1
ASSET VALUE, THREAT/HAZARD, VULNERABILITY, AND RISK 1-29

❍ The value of risk reduction to the school 

❍ Frequency with which the benefits of the mitigation measures 

will be realized

❍ The deterrence or preventive value of the mitigation measures

❍ The expected lifespan of the mitigation measures and the 

time value of money

To evaluate prospective mitigation measures, the design team 

should first calculate new values of risk based on how the installation or use of mitigation measures would change vulnerability 

and/or asset values. Some mitigation measures will affect multiple asset/threat risk values. After the amount of risk reduction 

each mitigation measure will produce has been calculated, the 

cost of each mitigation measure should be estimated using resources such as R.S. Means Construction Cost Data. The final 

step is to perform a benefit/cost analysis to determine which 

mitigation measures will produce the greatest reduction of risk 

at an acceptable cost. 

When dealing with manmade hazards and terrorism, it is much 

more difficult to predict how often an event will occur and the 

deterrent value of mitigation measures. Although there are historical data to help predict how often natural hazards such as 

floods or tornadoes occur in various regions, the probability or 

frequency of manmade hazards/threats is not known. Therefore, 

subjective approaches for frequency must be combined with 

quantitative estimates of cost-effectiveness. 

Additionally, the deterrent or preventive value of a mitigation 

measure is also difficult to quantify. Deterrence, in the case 

of terrorism, may also have a secondary impact in that, once a 

school is “hardened,” a terrorist may turn to a less protected 

building, changing the likelihood of an attack for both targets. 

For example, the Murrah Federal Building in Oklahoma City 

became the target of an aggressor when he was deterred from 

attacking his primary target, the FBI building, because it was too 

difficult to get the attack vehicle close to the target. He was able 
1-30 ASSET VALUE, THREAT/HAZARD, VULNERABILITY, AND RISK 

to park immediately adjacent to the Murrah Federal Building 

and successfully target the Bureau of Alcohol, Tobacco, and Firearms (ATF).

All these factors should be considered when calculating the value 

of mitigation measures, and weighing their value against their 

cost. Ideally, sufficient resources would be available to achieve a 

desired level of protection against design basis threats through 

mitigation measures. This is not always the case, so it is also important that every school identify or designate an appropriate 

authority that is authorized to accept risk on behalf of the school. 

Sometimes when decisions are left up to committees or personnel 

at an inappropriate level, poor choices or decisions can be made.

It is also essential to maintain analytic integrity and objectivity 

during the assessment process in order to achieve an honest and 

unbiased risk assessment. Legitimate differences of professional 

opinion may occur; therefore, it is also important that the process 

be transparent and repeatable. For example, there could be an 

honest disagreement about the threat rating assigned to an “electronic attack to destroy school records.” An open and repeatable 

methodology facilitates healthy debate to help the risk acceptance 

authority, who is ultimately responsible, make informed decisions. 

In sum, the risk management process is a benefit/cost analysis to 

decide and prioritize which mitigation measures to implement to 

achieve the desired level of protection with available resources. 

This is accomplished by repeating risk assessment calculations adjusting for how mitigation measures change a school’s asset values 

and vulnerabilities. As pointed out earlier, mitigation measures 

may also change how an aggressor views a school, thus changing 

the threat assessment as well. 
SITE AND LAYOUT DESIGN GUIDANCE 2

SITE AND LAYOUT DESIGN GUIDANCE 2-1

T his chapter discusses comprehensive architectural and 

engineering design considerations (mitigation measures) 

for the school site, from the property line to the school 

building, including: land use, site planning, stand-off distance, 

controlled access zones, entry control and vehicular access, signage, parking, loading docks and service access, physical security 

lighting, and site utilities. The intent of this guidance is to provide 

concepts for integrating mitigation strategies to the design basis 

threats as identified during the risk assessment. Integrating security requirements into a larger, more comprehensive approach 

necessitates achieving a balance among many objectives such as 

reducing risk; facilitating proper school building function; aesthetics and matching architecture; creating a school environment 

conducive to learning; and hardening of physical structures beyond required building codes and standards for added security. 

The design community must work closely with school districts 

and school administrators to ensure that the optimal balance of 

all these considerations is achieved; thus, coordination within 

the design team is critical. Many school asset protection objectives can be achieved during the early stages of the design process 

when mitigation measures are the least costly and most easily 

implemented. Planners, architects, and landscape designers play 

an important role in identifying and implementing crucial asset 

protection measures while considering land use; site selection; the 

orientation of buildings on the site; and the integration of vehicle 

access, control points, physical barriers, landscaping, parking, and 

protection of utilities to mitigate threats. 

It is important to remember that the nature of any threat is always 

changing. Although indications of potential future threats may 

be scarce during the design stage, consideration should be given 

to accommodating enhanced protection measures in response to 

future threats that may emerge. School protection objectives must 

be balanced with other design objectives, such as the efficient use 
2-2 SITE AND LAYOUT DESIGN GUIDANCE 

of land and resources, and must also take into account existing 

physical, programmatic, and fiscal constraints.

2.1 LAND USE CONSIDERATIONS

Land use is a broad planning process that encompasses zoning 

ordinances, subdivision regulations, and master planning. Regulating land use development has been a common practice in the 

United States for many years, with numerous regulations and 

other tools in use by state and local governments to influence 

the configuration of urban sites. Comprehensive planning can 

encourage certain types of development, incentives, allocation 

of resources, and capital improvement programs oriented to 

improve the security of areas vulnerable to manmade disasters. 

In most cases, sound site planning will increase the land area 

needed for individual school buildings and maximize the protection measures to be adopted. Other potential terrorist targets 

in the surrounding area should also be considered. Students 

and teachers might be killed or injured by collateral damage 

from a terrorist attack directed at another nearby facility. When 

designing a school, the designer should consider external and 

internal land use design concerns, including the characteristics 

of the surrounding area (e.g., construction type, occupancies, 

and the nature and intensity of adjacent activities), as well as the 

implications of these characteristics for the protection of the students, faculty, and staff on the school site under consideration. 

The amount of land available on the site for stand-off and the 

inherent ability of the school site to accommodate the implementation of natural and manmade antiterrorism and security 

design features could help the designers to determine if other 

measures such as hardening the school building should also be 

considered.

It is important to recognize that conflicts sometimes arise between security-oriented site design and conventional site design. 

For example, open circulation and common spaces (which are 

desirable for conventional design) may be detrimental to certain 

aspects of security. 
SITE AND LAYOUT DESIGN GUIDANCE 2-3

When designing new school buildings or evaluating existing 

schools, the designer should evaluate key protection measures to 

ensure they are appropriate, desirable, and cost-effective in terms 

of mitigating the risk of potential terrorist attacks. Security measures must be evaluated carefully to understand which measures 

are truly beneficial and which are not practical.

When making decisions about site antiterrorism and security, designers should consider the following:

❍ Adjacent land use and zoning plans for potential development 

that would impact security within the school (assess by using 

land use maps and Geographic Information Systems [GISs])

❍ Building footprint(s) relative to total land available

❍ Building location(s) or, if undeveloped, suitable building 

location(s) relative to the site perimeter and adjacent land 

uses; distance between the perimeter fence and improved 

areas off site 

❍ Access via foot, road, rail, water, and air; suitability to support 

a secure perimeter

❍ Current and planned infrastructure and its vulnerabilities, 

including easements, tunnels, pipes, and rights-of-way 

❍ Infrastructure nodes that constitute single-point vulnerabilities 

❍ Adjacent land uses and occupancies that could enable or 

facilitate attacks or that are potential targets themselves and 

thus present collateral damage or cascading failure hazards

❍ Proximity to fire and police stations, hospitals, shelters, and 

other critical facilities that could be of use in an attack

❍ Presence of natural physical barriers such as water features, 

dense vegetation, and terrain that could provide access 

control and/or shielding, or suitability of the site for the 

incorporation of such features

❍ Topographic and climatic characteristics that could affect the 

performance of chemical agents and other weapons 
2-4 SITE AND LAYOUT DESIGN GUIDANCE 

❍ Observability from outside site boundaries; ability of vegetation 

in proximity to building or site to screen covert activity 

2.2 SITE PLANNING

The single most important goal in planning a site to resist terrorism and security threats is the protection of life, property, and 

operations. Decision-making in support of this purpose should 

be based first and foremost on a comprehensive assessment of 

the manmade threats and hazards so that planning and design 

countermeasures are appropriate and effective in the reduction of 

vulnerability and risk as described in Chapter 1. It is important to 

recognize that a given countermeasure can mitigate one or more 

vulnerabilities, but may be detrimental to other important design 

goals. This section will highlight several aspects of site design and 

will present some of the unique characteristics arising from their 

application to antiterrorism and security.

2.2.1 Site Design

Because the economics of development dictate the construction of schools, security concerns should be evaluated carefully. 

Conflicts sometimes arise between security site design and conventional site design. For example, open circulation and common 

spaces, which are desirable for conventional school design, are 

often undesirable for security design. To maximize safety, security, 

and sustainability, designers should implement a holistic approach 

to site design that integrates form and function to achieve a balance among the various design elements and objectives. Even if 

resources are limited, significant value can be added to a project 

by integrating security considerations into the more traditional 

design tasks in such a way that they complement, rather than compete with, the other elements. 

2.2.2 Layout and Form

The overall layout of a school site (e.g., the placement and form of 

its buildings, infrastructures, and amenities) is the starting point 

for development. Choices made during this stage of the design 
SITE AND LAYOUT DESIGN GUIDANCE 2-5

process will steer decision-making for the other elements of the 

site. A number of aspects of site layout and building type present 

security considerations and are discussed below.

❍ Clustered versus dispersed functions. There is a strong 

correlation between building functions and building 

layout and forms. Typically, the former dictates the other 

two. Depending on the site characteristics, the occupancy 

requirements, and other factors, school buildings may cluster 

key functions in one particular area or have these functions 

designed in a more dispersed manner. Both patterns have 

compelling strengths and weaknesses in terms of security.

Concentrating key functions in one place may create a targetrich environment and increase the risk of collateral impacts. 

Additionally, it increases the potential for the establishment 

of more single-point vulnerabilities, such as indicated in 

Figure 2-1. This figure shows several key functions grouped in 

a particular area of the building (i.e., the mechanical rooms, 

stairs, telephone switch room, and loading docks). If these areas 

become a target, the school may be closed for a substantial 

period of time, even if the attack is not severe and the rest of 

the school remains unharmed. However, grouping high-risk 

activities, concentrations of personnel, and critical functions 

into a cluster can help maximize stand-off from the perimeter 

and create a “defensible space.” This also helps to reduce the 

number of access and surveillance points, and minimize the size 

of the perimeter needed to protect the school areas.

In contrast, the dispersal of key functions reduces the risk 

that an attack on any one part of the site will impact the other 

parts. However, this could also have an isolating effect and 

reduce the effectiveness of on-site surveillance, increase the 

complexity of security systems and emergency response, and 

create a less defensible space.

To the extent that site, economic, and other factors allow, the 

designer should consolidate school designs that are functionally 
2-6 SITE AND LAYOUT DESIGN GUIDANCE 

compatible and have similar threat levels. For example, visitor 

areas and receiving/loading areas constitute a school’s innermost 

line of defense, because they are the first places where people 

and materials enter the school building. Logically, they should 

be physically separated from other key functions such as the main 

operational areas or where people concentrate. 

❍ School building orientation. The orientation of a school 

building can have significant impact on its performance, not 

only in terms of energy efficiency, but also the ability to protect 

occupants (see Figure 2-2). A school building’s orientation 

relative to its surroundings defines its relationship to that 

area. In aesthetic terms, a school building can open up to the 

area or turn its back; it can be inviting to those outside, or it 

can “hunker down” defensively. The physical positioning of a 

building relative to its surroundings may seem more subtle, 

but can be a greater determinant of this intangible quality than 

exterior aesthetics. Nevertheless, the proximity of a vulnerable 

Figure 2-1 Non-redundant critical functions collocated near loading dock
SITE AND LAYOUT DESIGN GUIDANCE 2-7

façade to a parking area, street, adjacent site, or other area that 

is accessible to vehicles and/or difficult to observe can greatly 

contribute to its vulnerability. This illustrates one way in which 

protective requirements can be at odds with otherwise good 

design. A strong, blank wall with no glazing will help to protect 

students, faculty, staff, property, and operations within from a 

blast, but the lack of windows removes virtually all opportunity 

for the faculty and staff to monitor activities outside and take 

appropriate protective actions in a timely manner. Designers 

should consider such trade-offs early in the design process, in 

an effort to determine an acceptable level of risk.

Figure 2-2 

Clustering to enhance surveillance 

opportunities while minimizing views 

into buildings

SOURCE: WLC ARCHITECTS, INC.
2-8 SITE AND LAYOUT DESIGN GUIDANCE 

❍ Open space. The incorporation of open space into school 

site design presents a number of benefits. First and foremost 

is the ability to easily monitor an area and detect intruders, 

vehicles, and weapons. Closely related to this benefit is the 

stand-off value of open space; as discussed in Chapter 4, blast 

energy decreases as the inverse of the cube of the distance 

from the seat of the explosion, so every additional increment 

of distance provides increasingly more protection. In addition, 

pervious open space allows stormwater to percolate back 

into the ground, reducing the need for culverts, drainage 

pipes, manholes, and other covert site access and weapon 

concealment opportunities. Also, if the open space is 

impassible for vehicles (as in the case of a wetland or densely 

vegetated area), it can provide not only environmental and 

aesthetic amenities, but prevent vehicle intrusion as well.

❍ Infrastructure and lifelines. Providing power, gas, water, 

wastewater, and communications services is one of the 

most basic requirements of any school development. At 

the site scale, all critical lifelines should have at least one 

layer of redundancy, or backup. By eliminating single-point 

vulnerabilities, designers will reduce the chance that service 

will be interrupted if an attack damages or destroys a lifeline 

either outside the school perimeter or on site. It is important 

to note that collocating a backup lifeline with its primary 

lifeline does not eliminate single-point vulnerability; only 

physical separation can substantially increase the likelihood of 

continuity of service. 

Additionally, all controls, interconnections, exposed lines, 

and other vulnerable elements of school infrastructure 

systems should be protected from access and exploitation 

by surveillance and/or physical countermeasures. Service 

entrances and other secondary access points should be 

monitored and access-controlled; special attention should also 

be paid to any locations where multiple systems or primary 

and backup systems come together, such as control rooms and 

mechanical spaces. Again, these facilities should be designed 
SITE AND LAYOUT DESIGN GUIDANCE 2-9

for maximum observability, including the use of opportunity 

reduction and target hardening strategies where appropriate, 

and should be equipped with adequate lighting and 

emergency communications capabilities wherever possible. For 

additional information, see Sections 2.9 and 2.10.

2.2.3 Vehicular and Pedestrian Circulation

The movement of people and materials into, through, and out of a 

school facility is determined by the design of its access, circulation, 

and parking systems. Such systems should be designed to maximize efficiency while minimizing conflicts between vehicle and 

pedestrian modes. Designers should begin with an understanding 

of the school’s transportation requirements based on an analysis 

of how the school will be used. This includes studying the number 

and types of access points that are required, bus requirements, the 

parking volume needed, where users need to go to and from, and 

the modes of transportation they will use. Several aspects of transportation planning can impact security and are discussed below.

❍ Roadway network design. Streets are generally designed to 

minimize travel time and maximize safety, with the end result 

typically being a straight path between two or more endpoints. 

Although a straight line may be the most efficient course, 

designers should use caution when orienting streets relative 

to school buildings requiring high protection. Designers 

should design a roadway system to minimize vehicle velocity, 

thus using the roadway itself as a protective measure. This is 

accomplished through the use of several strategies.

First, straight-line or perpendicular approaches to school 

buildings should not be used in a school at high risk, because 

these give vehicles the opportunity to gather the speed 

necessary to ram through protective barriers and crash into or 

penetrate buildings. Instead, approaches should be parallel 

to the façade, with berms, high curbs, appropriate trees, or 

other measures used to prevent vehicles from departing the 

roadway. A related technique for reducing vehicle speeds is 

the construction of serpentine (curving) roadways with tight-
2-10 SITE AND LAYOUT DESIGN GUIDANCE 

radius corners. Existing streets can be retrofitted with barriers, 

bollards, swing gates, or other measures to force vehicles 

to travel in a serpentine path. Again, high curbs and other 

measures should be installed to keep vehicles from departing 

the roadway in an effort to avoid these countermeasures. 

Less radical than these techniques are traffic calming strategies, 

which seek to use design measures to cue drivers as to the 

acceptable speed for an area. These include raised crosswalks, 

speed humps and speed tables, pavement treatments, bulbouts, 

and traffic circles. In addition to creating a more pedestrianfriendly environment, which increases “eyes on the street” 

surveillance, designing roadways to physically limit speeds can 

have the added benefits of increasing safety and, subsequently, 

lowering liability. Designers should be aware, however, that many 

of these techniques can have detrimental effects for emergency 

response, including slowing response time, interfering with 

en route emergency medical treatment, and increasing the 

difficulty of maneuvering fire apparatus. They also may present 

problems for snow removal, and their outer ends should remain 

flat so that bicycles can proceed unimpeded.

❍ Parking. Surface lots can be designed and placed to keep 

vehicles away from school buildings, but they can consume large 

amounts of land and, if constructed of impervious materials, 

can contribute greatly to stormwater runoff. They can also be 

hazardous for pedestrians if dedicated pedestrian pathways are 

not provided. For additional information, see Section 2.7.

2.2.4 Landscape and Urban Design

Designing to meet user needs while maintaining stewardship of 

the natural and built environments becomes increasingly more 

challenging when security requirements are factored in. Design 

principles at the school site should include an emphasis on selection of low-impact development techniques and environmental 

stewardship; compatibility of context and relationship with adjacent uses, forms, and styles; establishment of scale and identity 
SITE AND LAYOUT DESIGN GUIDANCE 2-11

through aesthetic design; connectivity among buildings, uses, activities, and transportation modes; resource conservation; cultural 

responsiveness; and the creation of appealing public spaces. These 

objectives are generally achieved through the work of two closely 

related disciplines, landscape design and urban design. For the 

purposes of this document, these two disciplines are virtually overlapping and will, therefore, be addressed together.

❍ Landscape design. Many landscape features can be used in 

school design to enhance security. Landscape design features 

should be used to create the level of protection without turning 

the school into a fortress. Elements such as landforms, water 

features, and vegetation are among the building blocks of 

attractive and welcoming spaces, and they can also be powerful 

tools for enhancing security. These features can be used not only 

to define or designate a space, but also to deter or prevent hostile 

surveillance or unauthorized access. Vegetative groupings and 

landforms can even provide some level of blast shielding. Stands of 

trees, earthen berms, and similar countermeasures generally cannot 

replace setbacks, but they can offer supplementary protection. 

However, landscaping can also have detrimental impacts for 

safety and security, and designers should consider the unique 

requirements of the school project to ensure that the landscape 

design elements they choose will be appropriate and effective. 

With careful selection, placement, and maintenance, 

landscape elements can provide visual screening that protects 

school gathering areas and other activities from surveillance 

without creating concealment for covert activity. However, 

dense vegetation in close proximity to a school building can 

screen illicit activity and should be avoided. Additionally, thick 

ground cover such as English ivy or vegetation over 4 inches 

tall such as monkey grass can be used to conceal bombs and 

other weapons; in setback clear zones, vegetation should 

be selected and maintained with eliminating concealment 

opportunities in mind. Similarly, measures to screen visually 

detractive components such as transformers, trash compactors, 

and condensing units should be designed to minimize 

concealment opportunities for people and weapons.
2-12 SITE AND LAYOUT DESIGN GUIDANCE 

❍ Urban design. Numerous urban design elements present 

opportunities to provide school security. The scale of the 

streetscape should be appropriate to its primary users, and it 

can be manipulated to increase the comfort level of desired 

users while creating a less inviting atmosphere for users 

with malicious intent. However, even at the pedestrian scale, 

certain operational requirements must be accommodated. For 

example, although efficient pedestrian and vehicle circulation 

systems are important for school functions and operations, 

they are also critical for emergency response, evacuation, and 

egress, and must be able to accommodate vehicles up to the 

largest fire apparatus in the community. Furthermore, despite 

an emphasis on downsizing the scale of the streetscape, it is 

critical to maintain the maximum stand-off distance possible 

between vehicles and structures. 

At the school perimeter, walls and fences used for space 

definition may be hardened to resist the impact of a weaponladen truck; however, planters, bollards, or decorative 

boulders could accomplish the same objective in a much more 

aesthetically pleasing manner. Such an approach also creates 

permeability, which would allow pedestrians and cyclists to 

more easily move through the space. 

Landscape and urban design inherently define the “lines of 

sight” in a space. These techniques seek to deny aggressors a 

“line of sight” to a potential target, either from on or off site. This 

increases the protection of sensitive information and operations 

by using stand-off weapons (see Figures 2-3 and 2-4). In addition 

to the use of various types of screening options, anti-surveillance 

measures (e.g., using building orientation, landscaping, 

screening, and landforms) to block sight lines can also be used.

Depending on the circumstances, landforms can be either beneficial or detrimental to anti-surveillance. Elevated sites may 

enhance surveillance of the surrounding area from inside the 

facility, but may also allow observation of on-site areas by adversaries. School buildings should not be sited immediately adjacent 
SITE AND LAYOUT DESIGN GUIDANCE 2-13 SOURCE: U.S. AIR FORCE, INSTALLATION FORCE PROTECTION GUIDE

Figure 2-4 Improper school siting and view relationships

SOURCE: U.S. AIR FORCE, INSTALLATION FORCE PROTECTION GUIDE

to higher surrounding terrain, unsecured buildings owned by 

unfamiliar parties, and vegetation, drainage channels, ditches, 

ridges, or culverts that can provide concealment. For high-risk 

school buildings, it may be necessary to provide additional protection by creating a clear zone immediately adjacent to the 

structure that is free of all visual obstructions or landscaping (see 

Figure 2-5). The clear zone facilitates monitoring of the immediate vicinity and visual detection of attacks. Walkways and other 

circulation features within a clear zone should be located so that 

buildings do not block views of pedestrians and vehicles. If clear 

zones are implemented, it may be necessary to implement other 

anti-surveillance measures.

Figure 2-3 Blocking of sight lines
2-14 SITE AND LAYOUT DESIGN GUIDANCE 

2.3 STAND-OFF DISTANCE

The most cost-effective solution for mitigating explosive effects on school buildings is to keep explosives as far away from 

them as possible. The distance between an asset and a threat 

is referred to as the stand-off distance as shown in Figure 2-6. 

There is no ideal stand-off distance; it is determined by the type 

of threat, the type of construction, and desired level of protection. The easiest and least costly opportunity for achieving 

appropriate levels of protection against terrorist threats is to 

incorporate sufficient stand-off distance into school designs. 

Maximizing stand-off distance also ensures that there is opportunity in the future to upgrade school buildings to meet increased 

threats or to accommodate higher levels of protection. Stand-off 

distance must be coupled with appropriate building hardening 

as discussed in Chapter 3, to provide the necessary level of protection to the school.

Figure 2-5 Clear zone with unobstructed views

SOURCE: U.S. AIR FORCE, INSTALLATION FORCE PROTECTION GUIDE
SITE AND LAYOUT DESIGN GUIDANCE 2-15

Figure 2-6 Concept of stand-off distance

For schools located in high-risk areas, additional considerations 

follow:

❍ The first mode of site protection is to create “keep out zones” 

that can ensure a minimum guaranteed distance between an 

explosion (i.e., from a vehicle) and the school structure. 

❍ The perimeter line is the outermost line that can be protected 

by the security measures incorporated during the school 

design process. It is recommended that the perimeter line 

be located as far as is practical from the building exterior. 

Many vulnerable school buildings are located in urban areas 

where only the exterior wall of the building stands between 

the outside world and the building occupants. In this case, 

the options are obviously limited. Often, the perimeter line 

can be pushed out to the edge of the sidewalk by means of 

bollards, planters, and other obstacles. To push this line even 

further outward, restricting or eliminating parking along the 

curb often can be arranged with local authorities. In some 

extreme cases, elimination of loading zones and the closure of 

streets are an option.

SOURCE: U.S. AIR FORCE, INSTALLATION 

FORCE PROTECTION GUIDE
2-16 SITE AND LAYOUT DESIGN GUIDANCE 

❍ “Keep out zones” can be achieved with perimeter barriers that 

cannot be compromised by vehicular ramming. A continuous 

line of security should be installed along the perimeter of 

the site to protect it from unscreened vehicles and to keep all 

vehicles as far away from the school as possible.

❍ The following critical building components should be located 

away from main entrances, vehicle circulation, parking, 

and maintenance areas. If this is not possible, harden as 

appropriate:

• Emergency generator, including fuel systems, day tank, fire 

sprinkler, and water supply

• Normal fuel storage

• Telephone distribution and main switchgear

• Fire pumps

• Building control centers

• Uninterrupted power supply (UPS) systems controlling 

critical functions

• Main refrigeration systems if critical to building operation

• Elevator machinery and controls

• Shafts for stairs, elevators, and utilities

• Critical distribution feeders for emergency power

2.4 CONTROLLED ACCESS ZONES 

For a school at high risk, one method to attain the appropriate 

protection is with the creation of a controlled access zone. These 

zones define minimum distances between a school building and 

potential threats through the installation of barriers (such as 

bollards, planters, fountains, walls, and fences). The barriers are 

designed to withstand assaults by terrorist vehicles; however, their 

placement must be designed to allow for access by fire and rescue 

vehicles in the event of an emergency. Selection of barriers is 
SITE AND LAYOUT DESIGN GUIDANCE 2-17 SOURCE: U.S. AIR FORCE, INSTALLATION FORCE PROTECTION GUIDE

based on operational considerations related to vehicle access and 

parking. Good design principles for high-risk schools endorse the 

complete surround of a school building with a stand-off zone that 

has perimeters set at distances that consider threat levels, desired 

level of protection, building construction, and land availability. 

Entry into the controlled area should only be through an entry 

control point.

When designing schools at high risk, controlled access zones may 

be exclusive or non-exclusive, as shown in Figure 2-7. An exclusive 

zone is the area surrounding a school building within the exclusive control of the building. Anyone entering an exclusive zone 

must have a purpose related to the building. A non-exclusive zone 

is either a public right-of-way or a particular area related to the 

main school building.

Figure 2-7 Exclusive and non-exclusive zones
2-18 SITE AND LAYOUT DESIGN GUIDANCE 

The following are some security considerations applicable to controlled access zones and enforcement:

❍ Design and select barriers based on threat capabilities.

❍ If the limited availability of land precludes the creation of an 

exclusive zone, the use of screening surrounding the school 

building is an alternative. 

❍ Design and locate security devices to establish consistent 

rhythm patterns within the site. Incorporate subtle and 

aesthetically pleasing security measures to reach the desired 

level of protection.

❍ Locate security measures so that they do not impede the free 

access to school public entrances or internal pedestrian flow. 

Miscellaneous decorative elements (e.g., flag poles, fountains, 

pools, gardens, and similar features) may be located within 

access ways to slow movement or restrict access.

❍ Use a combination of barriers. Some barriers are fixed 

and obvious (fences and gates), while others are passive 

(sidewalks far away from buildings, curbs with grassy areas, 

etc.). See Figure 2-8.

Figure 2-8 Sample bollard applications
SITE AND LAYOUT DESIGN GUIDANCE 2-19

❍ Consider using landscape materials to create barriers that are 

soft and natural rather than manmade where physical barriers 

are required.

❍ Use vehicles as temporary physical barriers by placing them in 

front of buildings or across access roads.

❍ Maintain as much stand-off distance as possible between 

potential vehicular bombs and the school building. 

• Provide traffic obstacles near entry control points to slow 

down traffic. 

• Consider vehicle barriers at building entries and drives. 

• Offset vehicle entrances from the direction of a vehicle’s 

approach to force a reduction in speed.

• Position gates and perimeter boundary fences outside the 

blast vulnerability envelope, when possible.

• Provide a vehicle crash resistance system in the form of a 

low wall or earth berm, if the threat level warrants it.

❍ Design entry control points (if provided) to screen the 

building from vehicles entering it.

❍ Provide passive vehicle barriers to keep stationary vehicle 

bombs at a distance from the school building.

• Use high curbs, low berms, shallow ditches, trees, shrubs, 

and other physical separations to keep stationary bombs at a 

distance. 

• Do not allow vehicles to park next to perimeter walls of the 

secured area. Consider using bollards or other devices to 

keep vehicles away.

❍ Provide adequate lighting to aid in threat detection in 

controlled access zones.

❍ Use CCTV to control entry points, the site perimeter, and 

exclusive and non-exclusive zones. 
2-20 SITE AND LAYOUT DESIGN GUIDANCE 

2.5 ENTRY CONTROL AND VEHICULAR 

ACCESS

In the case of a school, the objective of the design professional 

is to save lives by mitigating building damages and reducing the 

chances of a catastrophic collapse of the building at least until 

it is fully evacuated. Although there are many forms of attacks 

against a school, from the standpoint of school structural design, the vehicle bomb governs design because historically it has 

been used on multiple occasions by terrorists. Where a school 

perimeter barrier is required for security, it will be necessary to 

provide points of access through the perimeter for school users 

(i.e., students, faculty, staff, visitors, and service providers). An 

entry control point or guard building serves as the designated 

point of entry for site access. It provides a point for implementation of desired/required levels of screening and access control. 

The objective of the entry control point is to prevent unauthorized access to school grounds while maximizing the rate of 

authorized access by foot or vehicle. These measures will not be 

required for all schools; they may only be appropriate for schools 

considered at high risk. Designs should be flexible to allow 

implementation of increased security controls when schools are 

placed in high alert and easing of controls at lower threat levels. 

For a school considered to be at high risk, the following should 

be considered in the design of entry control points: 

❍ Design entry roads to schools so that they do not provide 

direct or straight-line vehicular access to the main building. 

Route major corridors away from key school areas and 

functions.

❍ Design access points at an angle to oncoming streets so that is 

difficult for a vehicle to gain enough speed to break through 

them.

❍ Minimize the number of access roads and entrances into a 

school.

❍ Provide a drop-off/pick-up lane for buses only.
SITE AND LAYOUT DESIGN GUIDANCE 2-21

❍ Minimize the number of driveways or parking lots that 

students will have to walk across to get to the school building.

❍ Designate an entry to the school for commercial, service, and 

delivery vehicles, preferably away from key school areas and 

functions, whenever possible.

❍ Design the entry control point and guard building so that the 

authorization of approaching vehicles and occupants can be 

adequately assessed, and the safety of both gate guards and 

approaching vehicles can be maintained when a school is 

placed at high alert). 

❍ Design (if they are required) traffic calming strategies and 

barriers (road alignment, retractable bollards, swing gates, 

or speed bumps) to control vehicle speed and slow incoming 

vehicles before they reach the gate so that entry control 

personnel have adequate time to respond to unauthorized 

activities. 

❍ Provide inspection areas that are not visible to the public. 

Place appropriate landscape plantings to accomplish 

screening.

❍ Provide pull-over lanes at site entry gates to check suspect 

vehicles. Also, provide a visitor/site personnel inspection area 

to inspect vehicles prior to allowing access to the school site. 

❍ Consider providing a walkway and turnstile for pedestrians 

and a dedicated bicycle lane. 

2.6 SIGNAGE

Signs are an important element of school security. They are 

meant to keep intruders out of restricted areas. Confusion over 

site circulation, parking, and entrance locations can contribute 

to a loss of site security. Signs should be provided off site and at 

school entrances; there should be on-site directional, parking, 

and cautionary signs for students, faculty, staff, visitors, service vehicles, and pedestrians. Unless required, signs should not identify 
2-22 SITE AND LAYOUT DESIGN GUIDANCE 

sensitive areas. A comprehensive signage plan should include the 

following:

❍ Prepare entry control procedures signs that explain current 

entry procedures for drivers and pedestrians.

❍ Prepare traffic regulatory and directional signs that control 

traffic flow and direct vehicles to specific appropriate points.

❍ Consider using street addresses or building numbers instead 

of detailed descriptive information inside the school grounds.

❍ Minimize the number of signs identifying high-risk areas; 

however, a significant number of warning signs should be 

erected to ensure that possible intruders are aware of entry 

into restricted areas. 

❍ Minimize signs identifying critical utility complexes (e.g., 

power stations and significant gas, water, and sewer). Post 

easily understandable signs to minimize accidental entry by 

unauthorized visitors into critical areas.

❍ In areas where English is one of two or more languages 

commonly spoken, warning signs must contain the other 

language(s) in addition to English. The signs should be 

posted at intervals of no more than 100 feet and should not 

be mounted on fences equipped with intrusion-detection 

equipment. 

❍ Locate variable message signs, which give information on 

site/organization special events and visitors, far inside site 

perimeters.

2.7 PARKING

Parking restrictions can help to keep potential threats away from 

a school building. In urban settings, however, curbside or underground parking is often necessary and sometimes difficult to 

control. Mitigating the risks associated with parking requires creative design measures, including parking restrictions, perimeter 

buffer zones, barriers, structural hardening, and other architectural 
SITE AND LAYOUT DESIGN GUIDANCE 2-23

and engineering solutions. The following considerations may help 

designers to implement parking measures for schools that may be 

at high risk:

❍ Locate vehicle parking areas away from school buildings to 

minimize blast effects from potential vehicle bombs.

❍ Provide separate parking areas for students, faculty, staff, and 

visitors who may be going in and out during the school day. 

(This allows the main student parking lot to be closed off 

during the school day.)

❍ If possible, locate visitor or general public parking near, but 

not on, the site itself. 

❍ Locate general parking in areas that provide the fewest 

security risks to school personnel. 

❍ Consider one-way circulation within a school parking lot to 

facilitate monitoring for potential aggressors. 

❍ Locate parking within view of occupied school buildings while 

maintaining stand-off. 

❍ Prohibit parking within the stand-off zone.

❍ Request appropriate permits to restrict parking in the curb 

lane for school vehicles or key employee parking only where 

distance from the building to the nearest curb provides 

insufficient setback, and compensating design measures do 

not sufficiently protect the building from the assessed threat. 

If necessary, use structural features to prevent parking. 

❍ Provide appropriate setback from parking on adjacent 

properties, if possible. Structural hardening may be required 

if the setback is insufficient. In new designs, it may be possible 

to adjust the location of the school building on the site to 

provide adequate setback from adjacent properties. 

❍ When establishing parking areas, provide emergency 

communications systems (e.g., intercom, telephones, etc.) at 

readily identified, well-lighted, CCTV monitored locations to 

permit direct contact with security personnel.
2-24 SITE AND LAYOUT DESIGN GUIDANCE 

❍ Provide parking lots with CCTV cameras connected to the 

security system and adequate lighting capable of displaying 

and videotaping lot activity. 

❍ If possible, prohibit parking beneath or within a school 

building.

❍ If parking beneath a building is unavoidable, limit access to 

the parking areas and ensure they are secure, well-lighted, 

and free of places of concealment.

❍ Apply the following restrictions If parking within a school 

building is required:

• Public parking with identification (ID) check

• School vehicles and school employees and students only

• Selected school employees only, or those requiring security

2.8 LOADING DOCKS AND SERVICE ACCESS

Loading docks and service access areas are commonly required for 

a school building and are typically desired to be kept as invisible 

as possible. For this reason, special attention should be devoted to 

these service areas in order to avoid intruders. Design criteria for 

school loading docks and service access include the following:

❍ Separate by at least 50 feet, loading docks and shipping and 

receiving areas in any direction from utility rooms, utility 

mains, and service entrances, including electrical, telephone/

data, fire detection/alarm systems, fire suppression water 

mains, cooling and heating mains, etc. 

❍ Locate loading docks so that vehicles will not be allowed 

under the building. If this is not possible, the service area 

should be hardened for blast. Loading dock design should 

limit damage to adjacent areas and vent explosive forces to 

the exterior of the building. 

❍ If loading zones or drive-through areas are necessary, monitor 

them and restrict height to keep out large vehicles.
SITE AND LAYOUT DESIGN GUIDANCE 2-25

❍ Avoid having driveways within or under school buildings.

❍ Provide adequate design to prevent extreme damage to 

loading docks. The floor of the loading dock does not need 

to be designed for blast resistance if the area below is not 

occupied and or does not contain critical utilities. In certain 

cases, significant structural damage to the walls and ceiling 

of the loading dock may be acceptable; however, the areas 

adjacent to the loading dock should not experience severe 

structural damage or collapse.

❍ Provide signage to clearly mark separate entrances for 

deliveries. 

2.9 PHYSICAL SECURITY LIGHTING

Security lighting can be provided for overall school ground/

building illumination and the perimeter to allow security personnel to maintain visual-assessment during darkness. It may 

provide both a real and psychological deterrent for continuous or 

periodic observation. Lighting is relatively inexpensive to maintain 

and may reduce the need for security personnel while enhancing 

personal protection by reducing opportunities for concealment 

and surprise by potential attackers. 

Provide sufficient lighting at entry control points to ensure adequate lighting for the area. Where practical, place lighting 

elements as high as possible to give a broader, more natural light 

distribution. This requires fewer poles (less hazardous to drivers) 

and is more aesthetically pleasing than standard lighting. 

The type of site lighting system used depends on the school’s 

overall security requirements. Four types of lighting are used for 

security lighting systems:

❍ Continuous lighting is the most common security lighting 

system. It consists of a series of fixed lights arranged to flood 

a given area continuously during darkness with overlapping 

cones of light.
2-26 SITE AND LAYOUT DESIGN GUIDANCE 

❍ Standby lighting has a layout similar to continuous lighting; 

however, the lights are not continuously lit, but are either 

automatically or manually turned on when suspicious activity is 

detected or suspected by the security personnel or alarm systems. 

❍ Movable lighting consists of manually operated, movable 

searchlights that may be lit during hours of darkness or 

only as needed. The system normally is used to supplement 

continuous or standby lighting.

❍ Emergency lighting is a backup power system of lighting that 

may duplicate any or all of the above systems. Its use is limited 

to times of power failure or other emergencies that render the 

normal system inoperative. It depends on an alternative power 

source such as installed or portable generators or batteries. 

Consider emergency/backup power for security lighting as 

determined to be appropriate.

2.10 SITE UTILITIES

Utility systems can suffer significant damage when subjected to 

the shock of an explosion. Some of these utilities may be critical 

for safely evacuating people from the school building. Their destruction could cause damage that is disproportionate to other 

building damage resulting from an explosion. To minimize the 

possibility of such hazards, apply the following measures:

❍ Where possible, provide underground, concealed, and 

protected utilities.

❍ Provide redundant utility systems (particularly electrical services) 

to support school security, life safety, and rescue functions.

❍ Consider quick connects for portable utility backup systems if 

redundant sources are not available.

❍ Prepare vulnerability assessments for all utility services 

to the school, including all utility lines, storm sewers, gas 

transmission lines, electricity transmission lines, and other 

utilities that may cross the site perimeter. 
SITE AND LAYOUT DESIGN GUIDANCE 2-27

❍ Protect drinking water supplies from waterborne 

contaminants by securing access points, such as manholes. 

If warranted, maintain routine water testing to help detect 

waterborne contaminants. 

❍ Minimize signs identifying critical utilities. Provide fencing to 

prevent unauthorized access and use landscape planting to 

conceal aboveground systems. 

❍ Locate petroleum, oil, and lubricants storage tanks and 

operations buildings downslope from all other occupied 

school buildings. Locate fuel storage tanks at least 100 feet 

from buildings.

❍ Consider providing utility systems with redundant or loop 

service, particularly in the case of electrical systems. Where 

more than one source or service is not currently available, 

provisions should be made for future connections. In the 

interim, consider “quick connects” at the building for 

portable backup systems.

❍ Decentralize a school’s communications resources, when 

possible; the use of multiple communication networks will 

strengthen the communications system’s ability to withstand 

the effects of a terrorist attack.

❍ Place trash receptacles as far away from the building as 

possible; trash receptacles should not be placed within 30 feet 

of a building. 

❍ Provide a school-wide public address system that extends from 

the interior to the exterior of buildings.

❍ Conceal and harden incoming utility systems within schools 

to provide blast protection, including burial or proper 

encasement wherever possible.

❍ Locate utility systems at least 50 feet from loading docks, front 

entrances, and parking areas.

❍ Route critical or fragile utilities so that they are not on 

exterior walls or on walls shared with mailrooms.
2-28 SITE AND LAYOUT DESIGN GUIDANCE 

❍ Ensure that the redundant utilities are not collocated or do 

not run in the same chases. This minimizes the possibility that 

both sets of utilities will be adversely affected by a single event.

❍ Ensure backup systems are located away from the systems 

components for which they provide backup.

❍ Mount all overhead utilities and other fixtures weighing 31 

pounds (14 kilograms) or more to minimize the likelihood 

that they will fall and injure school occupants. Design 

all equipment mountings to resist forces of 0.5 times the 

equipment weight in any direction and 1.5 times the 

equipment weight in the downward direction. This standard 

does not preclude the need to design equipment mountings 

for forces required by other criteria such as seismic standards.

❍ Ensure that access to crawl spaces, utility tunnels, and other 

means of under school building access is controlled to limit 

opportunities for aggressors placing explosives underneath 

buildings.

❍ Screen, seal, or secure all utility penetrations of the 

site’s perimeter to prevent their use as access points for 

unauthorized entry into the school site. If access is required 

for maintenance of utilities, secure all penetrations with 

screening, grating, latticework, or other similar devices.

2.11 SUMMARY OF SITE MITIGATION 

MEASURES

A general spectrum of site mitigation measures ranging from the 

least protection, cost, and effort going to the greatest protection, 

cost, and effort for a school site is presented below. Detailed 

discussions of individual measures can be found earlier in the 

chapter. This is a nominal ranking of mitigation measures. In 

practice, the effectiveness and cost of individual mitigation measures may be different for specific applications. Table 2-1 can 

be used by designers and school administrators to correlate the 

mitigation measures described in this chapter to specific terrorist 

threats and tactics. 
SITE AND LAYOUT DESIGN GUIDANCE 2-29

• Place trash receptacles as far away from the school building as possible.

• Remove any dense vegetation that may screen covert activity.

• Use thorn-bearing plant materials to create natural barriers. 

• Identify all critical resources in the school area (fire and police stations, hospitals, etc.) for design consideration.

• Identify all potentially hazardous facilities in the area (nuclear plants, chemical labs, etc.). 

• Use temporary passive barriers to eliminate straight-line vehicular access to areas of limited access.

• Use vehicles as temporary physical barriers during elevated threat conditions.

• Make proper use of signs for traffic control, building entry control, etc. Minimize signs identifying high-risk areas. 

• Identify, secure, and control access to all utility services to the school. 

• Limit and control access to all school crawl spaces, utility tunnels, and other means of under building access 

to prevent the planting of explosives.

• Utilize GIS to assess adjacent land use.

• Provide open space inside the fence along the school perimeter.

• Locate fuel storage tanks at least 100 feet from all occupied school buildings. 

• Block sight lines through building orientation, landscaping, screening, and landforms.

• Use temporary and procedural measures to restrict parking and increase stand-off. 

• Locate and consolidate high-risk land uses in the interior of the school site. 

• Select and design barriers based on threat levels. 

• Maintain as much stand-off distance as possible from potential vehicle bombs. 

• Separate backup utility systems. 

• Conduct periodic water testing to detect waterborne contaminants. 

• Enclose the perimeter of the school. Create a single controlled entrance for vehicles (entry control point). 

• Establish law enforcement or security force presence for schools facing high threats.

• Install quick connects for portable utility backup systems.

• Install security lighting in areas where needed. 

• Install CCTV cameras in areas where needed.

• Mount all equipment to resist forces in any direction. 

• Include security and protection measures in the calculation of school land area requirements.

• Redesign and construct parking to provide adequate stand-off for vehicle bombs.

• Position buildings to permit occupants and security personnel to monitor the site.

• Do not site the school building adjacent to potential threats or hazards.

• Locate critical school building components away from the main entrance, vehicle circulation, parking, or 

maintenance area. Harden as appropriate.

• Provide a site-wide public address system and emergency call boxes at readily identified locations.

• Prohibit parking beneath or within a school building. 

• Redesign and construct access points at an angle to oncoming streets.

• Designate entry points for commercial and delivery vehicles away from high-risk areas.

• In urban areas, push the perimeter out to the edge of the sidewalk by means of bollards, planters, and other 

obstacles. For even better stand-off, push the line even farther outward by restricting or eliminating parking 

along the curb, eliminating loading zones, or through street closings.

• Provide intrusion detection sensors for all utility services to the school.

• Provide backup utility systems to support school security, life safety, and rescue functions.

• Conceal and/or harden incoming utility systems.

• Install active vehicle crash barriers. 
2-30 SITE AND LAYOUT DESIGN GUIDANCE 

Table 2-1 Correlation of Mitigation Measures to Threats*

■ The symbols indicate which of the protective 

measures shown in the left-hand column can be 

effective in countering the types of threats indicated 

across the top of the chart.

Moving Vehicle BombStationary Vehicle BombExterior AttackStand-off Weapons AttackArmed AttackCovert EntryMail and Supplies BombsAirborne ContaminationWaterborne Contamination

LAND USE CONSIDERATIONS

Locate high-risk land uses in the interior of the school site ■ ■ ■ ■ ■

Consolidate high-risk land uses ■ ■ ■ ■ ■

Include stand-off areas in land area requirements ■ ■ ■ ■

Consider effects of development off-property development ■ ■ ■ ■

SITE PLANNING

Maximize distance from perimeter fence and developed areas ■ ■ ■ ■ ■ ■

Site critical school facilities on higher ground ■ ■ ■ ■ ■ ■ ■

Avoid areas with adjacent high terrain or structures ■ ■ ■ ■ ■

Avoid areas with adjacent dense vegetation ■ ■ ■

Avoiding low-lying topographic areas ■ ■ ■ ■ ■

Site school facilities within view of other occupied facilities ■

Create complexes to enhance surveillance opportunities ■ ■ ■ ■ ■

Eliminate vehicle parking from interior of building complexes ■ ■

High surrounding terrain ■ ■ ■

Distance from non-school facilities ■ ■ ■ ■ ■ ■ ■ ■

Areas that provide concealment ■ ■ ■ ■ ■

Earth berms ■ ■ ■ ■

Bodies of water ■ ■ ■ ■ ■ ■

Depressions ■ ■ ■

Vehicle access ■ ■

Dense thorn-bearing vegetation ■ ■

Vegetation screens ■ ■ ■ ■ ■

Location of trash receptacles ■
SITE AND LAYOUT DESIGN GUIDANCE 2-31 Moving Vehicle Bomb Stationary Vehicle Bomb Exterior Attack Stand-off Weapons Attack Armed Attack Covert Entry Mail and Supplies Bombs Airborne Contamination Waterborne Contamination

Table 2-1: Correlation of Mitigation Measures to Threats* (continued)

STAND-OFF DISTANCE 

Stand-off zone ■ ■ ■ ■ ■

CONTROLLED ACCESS ZONES

Exclusive zone/Non-exclusive zone ■ ■ ■

Clear zone ■ ■ ■

Fencing and physical barriers ■ ■ ■ ■ ■ ■

Active barriers ■ ■ ■ ■ ■ ■

Passive barriers ■ ■ ■ ■

ENTRY CONTROL AND VEHICULAR ACCESS

Minimize access roads ■ ■ ■ ■

Control points ■ ■ ■ ■ ■ ■

Active monitoring ■ ■ ■ ■ ■ ■ ■ ■ ■

Provide enhanced protection at school entrances ■ ■ ■ ■ ■ ■

Include pull-over lanes at checkpoints to inspect vehicles ■ ■ ■ ■ ■ ■

Avoid straight-line vehicular access to high-risk areas ■ ■

Avoid straight-line entry approach roads ■ ■

Locate vehicle parking areas far from high-risk areas ■ ■

Provide separate service and delivery access ■ ■

Route major corridors away from high-risk areas ■ ■ ■ ■

Locate high-risk resources remote from primary roads ■ ■ ■ ■

Minimize directional identification signs ■ ■ ■ ■ ■ ■

Limit vehicular access to high-risk areas ■ ■ ■ ■ ■ ■

SIGNAGE

Minimize signage ■ ■ ■ ■ ■ ■ ■ ■ ■
2-32 SITE AND LAYOUT DESIGN GUIDANCE 

PARKING

View of parking ■

Parking under a building ■

Parking at interior of facility ■

Parking near high-risk areas ■

Parking in exclusive zone ■

One-way circulation ■ ■ ■ ■

LOADING DOCKS AND SERVICE ACCESS

Loading/unloading docks ■ ■

Driveways under facilities ■ ■

PHYSICAL SECURITY LIGHTING

Lighting ■ ■ ■

SITE UTILITIES

Provide protection at culverts, sewers, and pipelines ■ ■ ■

Provide protection at concrete trenches, storm drains, and duct 

systems ■ ■ ■

Provide and check locks on manhole covers ■ ■ ■

Minimize signs identifying utility systems ■ ■ ■

Provide fencing at critical utility complexes ■ ■

Use landscape planting to conceal aboveground systems ■ ■

Install utilities underground ■ ■ ■ ■ ■ ■ ■

Locate fuel/lube storage downslope and away from facilities ■ ■ ■ ■ ■ ■ ■

Provide redundant utility systems and loop service ■ ■ ■ ■ ■ ■ ■

Provide utility “quick disconnects” for portable backup systems ■ ■ ■ ■ ■ ■ ■ Moving Vehicle Bomb Stationary Vehicle Bomb Exterior Attack Stand-off Weapons Attack Armed Attack Covert Entry Mail and Supplies Bombs

Airborne ContaminationWaterborne Contamination

Table 2-1: Correlation of Mitigation Measures to Threats* (continued)
SITE AND LAYOUT DESIGN GUIDANCE 2-33 Moving Vehicle Bomb Stationary Vehicle Bomb Exterior Attack Stand-off Weapons Attack Armed Attack Covert Entry Mail and Supplies Bombs Airborne Contamination Waterborne Contamination

Table 2-1: Correlation of Mitigation Measures to Threats* (continued)

Decentralize communications resources ■ ■ ■ ■ ■ ■ ■

Use multiple communications networks ■ ■ ■ ■ ■ ■ ■

Conceal and protect network control centers ■ ■ ■ ■ ■ ■ ■

Public address system ■ ■ ■ ■

Underground utilities ■ ■ ■ ■ ■

Redundant utilities ■ ■ ■ ■ ■ ■

Quick disconnects ■ ■ ■ ■ ■

Remote fuel storage ■ ■ ■ ■ ■

2.12 CRIME PREVENTION THROUGH 

ENVIRONMENTAL DESIGN (CPTED)

CPTED is a crime reduction technique that has several key elements applicable to the analysis of building function and site 

design against physical attack. It is used by architects, city planners, landscape and interior designers, and law enforcement with 

the objective of creating a climate of safety in a community by designing a physical environment that positively influences human 

behavior. Although CPTED principles are not incorporated into 

the assessment process presented in this primer, it is useful to 

briefly discuss CPTED because it is often entwined with terrorism 

protection measures.

CPTED concepts have been successfully applied in a wide variety 

of applications, including streets, parks, museums, government 

* ADAPTED FROM U.S. AIR FORCE INSTALLATION FORCE PROTECTION GUIDE. 
2-34 SITE AND LAYOUT DESIGN GUIDANCE 

buildings, houses, and commercial complexes. The approach is 

particularly applicable to schools, where outdated facilities are 

common. Most schools in the United States were built 30 to 60 

or more years ago. Security issues were almost nonexistent at 

the time, and technology was dramatically different. As a result, 

building designs are not always compatible with today’s more security-conscious environment. 

According to CPTED principles, depending upon purely conventional physical security measures (e.g., security guards and metal 

detectors) to correct objectionable student behavior may have 

its limitations. Although employing physical security measures 

will no doubt increase the level of physical security, in some cases 

physical security measures employed as stand-alone measures 

may lead to a more negative environment, thereby enhancing 

violence. In short, employing stand-alone physical security measures may fail to address the underlying behavioral patterns that 

adversely affect the school environment. CPTED analysis focuses 

on creating changes to the physical and social environment that 

will reinforce positive behavior. 

CPTED builds on three strategies: 

❍ Territoriality (using buildings, fences, pavement, sign, and 

landscaping to express ownership)

❍ Natural surveillance (placing physical features, activities, and 

people to maximize visibility)

❍ Access control (the judicial placement of entrances, exits, 

fencing, landscaping, and lighting)

A CPTED analysis of a school evaluates crime rates, office-referral 

data, and school cohesiveness and stability, as well as core design 

shortcomings of the physical environment (e.g., blind hallways, 

uncontrolled entries, or abandoned areas that attract problem behavior). The application of CPTED principles starts with a threat 

and vulnerability analysis to determine the potential for attack 

and what needs to be protected. Protecting a school from physical 
SITE AND LAYOUT DESIGN GUIDANCE 2-35

attack by criminal behavior or terrorist activity, in many cases, only 

reflects a change in the level and types of threats. The CPTED 

process asks questions about territoriality, natural surveillance, 

and access control that can:

❍ Increase the effort to commit crime or terrorism

❍ Increase the risks associated with crime or terrorism

❍ Reduce the rewards associated with crime or terrorism

❍ Remove the excuses as to why people do not comply with the 

rules and behave inappropriately

The CPTED process provides direction to solve the challenges of 

crime and terrorism with organizational (people), mechanical 

(technology and hardware), and natural design (architecture and 

circulation flow) methods. 

CPTED concepts can be integrated into expansion or reconstruction plans for existing buildings as well as new buildings. 

Applying CPTED concepts from the beginning usually has minimal impact on costs, and the result is a safer school. Each school, 

district, and community should institute measures appropriate 

for their own circumstances because there is no a single solution 

that will fit all schools. 

Many CPTED crime prevention techniques for a school complement conventional terrorism and physical attack prevention 

measures. For example, as part of the CPTED strategy of improving territoriality, schools are encouraged to direct all visitors 

through one entrance that offers contact with a receptionist who 

can determine the purpose of the visit and the destination, and 

provide sign-in/sign-out and an ID tag prior to building access. 

These CPTED measures are similar to and complement physical 

security entry control point stations.

However, in some cases, CPTED techniques can conflict with basic 

physical security principles. The CPTED strategy of natural surveillance calls for locating student parking in areas that allow ease 
2-36 SITE AND LAYOUT DESIGN GUIDANCE

of monitoring. A design that locates student parking close to the 

principal’s office also reduces vehicle stand-off and could create 

a vulnerability of the school structure to a vehicle bomb. In cases 

where CPTED techniques conflict with security principles, designers and school administrators should seek innovative solutions 

tailored to their unique situation.
BUILDING DESIGN GUIDANCE AND SAFETY PLANS 3

BUILDING DESIGN GUIDANCE AND SAFETY PLANS 3-1

T his chapter addresses explosive blast and CBR concerns 

from terrorist attacks, highlighting mitigation measures, 

including architectural, structural, and building envelope 

systems, and school safety plans. After the site design considerations to enhance protection presented in Chapter 2 have been 

taken into account, additional building design measures, such 

as hardening and CBR mitigation measures, must be considered 

to protect school occupants. Historically, the majority of fatalities that occur in terrorist attacks directed against buildings are 

due to building collapse. This was true for the Oklahoma City 

bombing in 1995 when 87 percent of the building occupants who 

were killed were in the collapsed portion of the Murrah Federal 

Building. 

When considering mitigation measures for explosive blast 

threats, the primary strategy is to keep explosive devices as far 

away from the school building as possible (maximize stand-off 

distance). This is usually the easiest and least costly way to achieve 

a desired level of protection. In cases where sufficient stand-off 

distance is not available to protect against progressive collapse 

of a school building (i.e., schools located in urban settings), 

hardening of the building’s structural systems may be required. 

Designers should try to minimize hazardous flying debris during 

an explosive event because a high number of injuries can result 

from flying glass fragments and debris from walls, ceilings, and 

non-structural features. Another consideration is to balance the 

hardening of the building envelope so that the columns, walls, 

windows, and glazing have approximately equal response for 

damage and injury/casualty for the design basis threat weapon 

at the available stand-off distance. Window design is the element 

that is usually the most diverse in conventional construction. 

Good blast engineering is a multi-disciplinary effort that requires 

the concerted efforts of the architect, structural engineer, mechanical engineer, and the other design team members in order 

to achieve a balanced building envelope.
3-2 BUILDING DESIGN GUIDANCE AND SAFETY PLANS 

When considering mitigation measures for CBR hazards, heating, 

ventilation, and air conditioning (HVAC) systems are of particular 

concern. A school building can provide protection against CBR 

agents released outdoors if the flow of fresh air is filtered or interrupted; however, HVAC systems can also become an entry point 

and distribution system for hazardous contaminants. If installed, 

HVAC air filtration and air-cleaning systems can reduce the effects 

of a CBR agent by removing the contaminants from the air within 

a building. There are a variety of ways to protect school building 

occupants from airborne hazards. These protective measures can 

be as simple as defining a protective action plan or as complex as 

strict design measures practical only for new construction. Specific 

HVAC design measures will be discussed in this chapter. In addition, Chapter 5 contains a discussion of CBR protective actions.

School building design should be optimized to facilitate emergency evacuation, rescue, and recovery efforts through effective 

placement, structural design, and redundancy of emergency exits 

and critical mechanical/electrical systems. Through effective 

structural design, the overall damage levels may be reduced to 

make it easier for people to get out safely and allow emergency 

responders to enter safely. The designer must also balance measures to protect people with the requirements of the Americans 

with Disabilities Act Accessibility Guidelines (ADAAG), Uniform 

Federal Accessibility Standards (UFAS), National Fire Protection 

Codes (NFPC), and all applicable local building codes. Additional 

information is available in FEMA 426, Reference Manual to Mitigate 

Potential Terrorist Attacks Against Buildings, and FEMA 427, Primer for 

Design of Commercial Buildings to Mitigate Terrorist Attacks.

3.1 ARCHITECTURAL

Several architectural considerations can be implemented to mitigate the effects of a terrorist bombing on a school facility. These 

considerations often cost nothing or very little if implemented 

early in the design process. 
BUILDING DESIGN GUIDANCE AND SAFETY PLANS 3-3

The shape of the school building can contribute to the overall 

damage to the structure. For example, “U” or “L” shaped buildings tend to trap shock waves, which may exacerbate the effect of 

explosive blasts. For this reason, it is recommended that re-entrant 

corners be avoided (see Figure 3-1). In general, convex rather 

than concave shapes are preferred when designing the exterior of 

a school building. Other considerations follow:

❍ Orient school buildings horizontally rather than vertically to 

reduce the building’s profile and exposure.

❍ Elevate the ground floors of school buildings above grade to 

prevent vehicles from being driven into the facility.

❍ Avoid eaves and overhangs, because they can be points of high 

local pressure and suction during blasts. When these elements 

are used, they should be designed to withstand blast effects.

❍ Locate utility systems away from likely areas of potential 

attack, such as loading docks, lobbies, and parking areas. 

❍ Orient glazing perpendicular to the primary facade to reduce 

exposure to blast and projectiles (see Figure 3-2).

❍ Avoid having exposed structural elements (e.g., columns) on 

the exterior of the school.

Figure 3-1 Re-entrant corners in a floor plan

SOURCE: U.S. AIR FORCE, INSTALLATION FORCE PROTECTION GUIDE
3-4 BUILDING DESIGN GUIDANCE AND SAFETY PLANS 

Figure 3-2 Glazed areas oriented perpendicularly away from streets

❍ Connect interior non-load bearing walls to the structure with 

flexible connections. 

❍ Place areas of high visitor activity away from key assets.

❍ Eliminate hiding places within the school building.

❍ Locate assets in areas where they are visible to more than one 

person.

❍ Use interior barriers to differentiate levels of security within a 

school building. 

❍ Stagger doors located across from one another in interior 

hallways to limit the effects of a blast through the school 

structure (see Figure 3-3).

❍ Provide foyers with reinforced concrete walls, and offset 

interior and exterior doors from each other in the foyer. 

❍ Locate stairwells required for emergency as remotely as 

possible from areas where blast events might occur.

SOURCE: U.S. AIR FORCE, INSTALLATION FORCE PROTECTION GUIDE
BUILDING DESIGN GUIDANCE AND SAFETY PLANS 3-5

❍ Wherever possible, do not 

discharge stairs into lobbies, 

parking, or loading areas.

❍ Separate unsecured areas of the 

main school building as much as 

possible. For example, a separate 

lobby pavilion or loading dock 

area outside of the main footprint 

of the building provides enhanced 

protection against damages and 

potential building collapse in the 

event of an explosion. This can 

also be done by creating internal 

“hard lines” or buffer zones, using 

secondary stairwells, elevator 

shafts, corridors, and storage areas 

between public and secured areas.

❍ Place parking areas outside the main footprint of the school 

building to reduce the vulnerability to catastrophic collapse.

3.2 BUILDING STRUCTURAL AND NONSTRUCTURAL SYSTEMS

For schools that require high security measures, explosive blast 

threats may govern building design. A structural engineer should 

determine the school design features needed to achieve the 

desired level of protection against the design blast threat, considering both the collapse of the school building as well as incipient 

injuries and fatalities of students, faculty, and staff. 

Progressive collapse is a situation where local failure of a primary 

structural component leads to the collapse of adjoining members which, in turn, leads to additional collapse. Hence the total 

damage is disproportionate to the original cause. Progressive collapse is a chain reaction of structural failures that follows from 

damage to a relatively small portion of a structure. SOURCE: U.S. AIR FORCE, INSTALLATION FORCE PROTECTION GUIDE

Figure 3-3 Offset doors through the foyer
3-6 BUILDING DESIGN GUIDANCE AND SAFETY PLANS 

All new school buildings should be designed with the intent of 

reducing the potential for progressive collapse as a result of an 

abnormal loading event, regardless of the required level of protection. The following structural characteristics (from GSA Progressive 

Collapse Analysis and Design Guidelines for New Federal Office Buildings 

and Major Modernization Projects, November 2000) should be considered in the initial phases of structural design. Incorporation of 

these features will provide a much more robust structure and decrease the potential for progressive collapse.

❍ Redundancy. The use of redundant lateral and vertical force 

resisting systems is highly encouraged when considering 

progressive collapse. Redundancy tends to promote a more 

robust structure and helps to ensure that alternate load paths 

are available in the case of a structural element(s) failure. 

Additionally, redundancy provides multiple locations for 

yielding to occur, which increases the probability that damage 

will be constrained.

❍ The use of ductile (flexible) structural elements and detailing. 

It is critical that both the primary and secondary structural 

elements be capable of deforming well beyond the elastic 

limit without experiencing structural collapse. Hence, the 

use of ductile construction materials (i.e., steel, cast-in-place 

reinforced concrete, etc.) for both the structural elements 

and connection detailing is encouraged. The capability of 

achieving a ductile response is imperative when considering 

an extreme redistribution of loading such as that encountered 

in a structural element(s) failure.

❍ Capacity for resisting load reversals. Both the primary and 

secondary structural elements should be designed to resist 

load reversals in the case of a structural element(s) failure.

❍ Capacity for resisting shear failure. Primary structural 

elements maintain sufficient strength and ductility under an 

abnormal loading event to preclude a shear failure. If the 

shear capacity is reached before flexural capacity, a sudden, 
BUILDING DESIGN GUIDANCE AND SAFETY PLANS 3-7

non-ductile failure of the element could potentially lead to a 

progressive collapse of the structure.

Both the GSA and DoD take a threat-independent approach to 

progressive collapse. The goal of a threat-independent approach 

is not to prevent collapse from a specific design threat, but to 

control and stop the continuing spread of damage after localized 

damage or localized collapse has occurred.

The GSA and DoD require that the structural response of a 

building be analyzed in a test that removes a key structural element (e.g., vertical load carrying column, section of bearing wall, 

beam, etc.) to simulate local damage from an explosion. If effective alternative load paths are available for redistributing the 

loads, originally supported by the removed structural element, the 

building has a low potential for progressive collapse. 

For higher levels of protection from blast, cast-in-place reinforced 

concrete is normally the construction type of choice. Other types 

of construction such as properly designed and detailed steel structures are also allowed. Several material and construction types, 

although not disallowed by these criteria, may be undesirable and 

uneconomical for protection from blast.

The following guidelines are 

commonly used to mitigate the 

effects of blast on structures and 

to mitigate the potential for progressive collapse. See sidebar for 

details and more guidance. 

❍ Use multiple barrier 

materials and construction 

techniques to mitigate the 

effects of blast on a structure 

at less expense than a single 

material or technique.

The following additional references are recommended:

• Biggs, John M. Introduction to Structural Dynamics. McGraw-Hill. 

(1964).

• The Institute of Structural Engineers. The Structural Engineer’s 

Response to Explosive Damage. SETO, Ltd., 11 Upper Belgrave 

Street, London SW1X8BH. (1995).

• Mays, G.S. and Smith, P.D. Blast Effects on Buildings: Design of 

Buildings to Optimize Resistance to Blast Loading. Thomas Telford 

Publications, 1 Heron Quay, London E14 4JD. (1995).

• National Research Council. Protecting Buildings from Bomb Damage. 

National Academy Press. (1995).
3-8 BUILDING DESIGN GUIDANCE AND SAFETY PLANS 

❍ Incorporate internal damping into the structural system to 

absorb blast impact.

❍ Use symmetric reinforcement to increase the ultimate load 

capacity of the structure.

❍ Incorporate design redundancy and alternative load paths 

to help mitigate blasts and reduce the chance of progressive 

collapse. The Murrah Federal Building’s structural system did 

not have any redundancy for the slab and beam systems. 

❍ Strengthen the structural system to help resist the effects of a 

blast. 

❍ Incorporate inelastic or post elastic design to allow the 

structure to absorb the energy of the explosion through 

plastic deformation.

❍ Recognize that components might act in directions for which 

they were not designed. This is due to the engulfment of 

structural members by blast, the negative phase, the upward 

loading of elements, and dynamic rebound of members. 

Making steel reinforcement (positive and negative faces) 

symmetric in all floor slabs, roof slabs, walls, beams, and girders 

will address this issue. Symmetric reinforcement also increases 

the ultimate load capacity of the members.

❍ Ensure that lap splices fully develop the capacity of the 

reinforcement.

❍ Stagger lap splices and other discontinuities.

❍ Control deflections around certain members, such 

as windows, to prevent premature failure. Additional 

reinforcement is generally required.

❍ Use wire mesh in plaster to reduce the incidence of flying 

fragments.

❍ Avoid the use of masonry when blast is a threat. Masonry walls 

break up readily and become secondary fragments during 

blasts. 
BUILDING DESIGN GUIDANCE AND SAFETY PLANS 3-9

❍ Use ductile connections for steel construction and develop 

as much moment connection as practical. Connections for 

cladding and exterior walls to steel frames should develop the 

capacity of the wall system under blast loads.

❍ Avoid single-point failures that can cascade, producing 

widespread catastrophic collapse. A prime example is the 

use of transfer beams and girders that, if lost, may cause 

progressive collapse and are, therefore, highly discouraged.

❍ Incorporate redundancy and alternative load paths into 

design to mitigate blast loads. One method of accomplishing 

this is to use two-way reinforcement schemes where possible.

❍ Minimize column spacing so that reasonably sized members 

can be designed to resist the design loads and increase the 

redundancy of the system. A practical upper level for column 

spacing is 30 feet for the levels of blast loads described herein.

❍ Minimize floor to floor heights. Unless there is an overriding 

architectural requirement, a practical limit is generally less 

than or equal to 16 feet.

❍ Use architectural or structural features that deny contact with 

exposed primary vertical load members in school lobbies. A 

minimum stand-off of at least 6 inches from these members is 

required.

❍ Minimize the use of venetian blinds and false ceilings, and 

locating equipment such as light fixtures, partitions, ductwork, 

and air conditioners above ceilings wherever possible. These 

items may become flying debris in the event of an explosion. 

Placing heavy equipment such as air conditioners near the 

floor rather than the ceiling is one idea for limiting this hazard; 

using exposed ductwork as an architectural device is another 

possibility.
3-10 BUILDING DESIGN GUIDANCE AND SAFETY PLANS 

3.3 BUILDING ENVELOPE

3.3.1 Building Exterior

The exterior envelope of the school building is the most vulnerable to an exterior explosive threat because it is the part of the 

building closest to the weapon. It also is a critical line of defense 

for protecting the occupants of the school building.

The design philosophy to be used here is that simpler is better. 

Generally simple geometries, with minimal ornamentation 

(which may become flying debris during an explosion) are recommended. If ornamentation is used, it is recommended that it 

consists of a lightweight material such as timber or plastic, which is 

less likely to become a projectile in the event of an explosion than, 

for example, brick, stone, or metal.

3.3.2 Exterior Wall Design

The exterior walls provide the first line of defense to prevent airblast pressures and hazardous debris from entering the school 

building. At a minimum, the objective of design is to ensure that 

these members fail in a flexible mode rather than in a brittle 

mode such as shear. The walls also need to be able to resist the 

loads transmitted by the windows and doors. Beyond ensuring a 

flexible failure mode, the exterior wall may be designed to resist 

the actual or reduced pressure levels of the defined threat. Special 

reinforcing and anchors should be provided around blast-resistant 

window and door frames. 

Poured-in-place reinforced concrete will provide the highest level 

of protection, but solutions like pre-cast concrete, reinforced 

concrete masonry unit (CMU) block, and metal studs may also be 

used to achieve lower levels of protection. 

For pre-cast panels, consider a minimum thickness of 5 inches 

with two-way reinforcing bars placed at spacing not greater than 

the thickness of the panel. Connections into the structure should 

provide as a straight a line of load transmittal as practical, using as 

few connecting pieces as possible.
BUILDING DESIGN GUIDANCE AND SAFETY PLANS 3-11

For CMU block walls, use 8-inch block walls, fully grouted with 

vertical centered reinforcing bars placed in each cell and horizontal reinforcement at each layer. Connections into the structure 

should be able to resist the ultimate lateral capacity of the wall. A 

preferred system is to have a continuous exterior CMU wall that 

laterally bears against the floor system. For increased protection, 

consider using 12-inch blocks with two layers of reinforcement.

For metal stud systems, use metal studs back to back and mechanically attached, to minimize lateral torsion effects. To catch exterior 

cladding fragments, attach a wire mesh to the exterior side of the 

metal stud system. The supports of the wall are to be designed to 

resist the ultimate lateral capacity load of the system.

When designing schools in areas perceived as high risk, engineers 

and architects should consider the following recommendations:

❍ Substitute strengthened building walls and systems when 

stand-off distances cannot be accommodated.

❍ Use ductile materials capable of very large plastic 

deformations without complete failure.

❍ Design exterior walls to resist the actual pressures and 

impulses acting on the exterior wall surfaces from the threats 

defined for the school building.

❍ Design exterior walls to withstand the dynamic reactions from 

the windows.

❍ Design exterior shear walls to resist the actual blast loads 

predicted from the threats specified. Consider shear walls 

that are essential to the lateral and vertical load bearing 

system, and that also function as exterior walls, to be primary 

structures.

❍ Consider reinforced concrete wall systems in lieu of masonry 

or curtain walls to minimize flying debris in a blast.
3-12 BUILDING DESIGN GUIDANCE AND SAFETY PLANS 

❍ Reinforced wall panels can protect columns and assist in 

preventing progressive collapse, because the wall will assist in 

carrying the load of a damaged column.

❍ Give special consideration to construction types that reduce 

the potential for collapse where exterior walls are not 

designed for the full design loads.

❍ Consider use of sacrificial exterior wall panels to absorb blast.

3.3.3 Window Design

Window systems (e.g., glazing, frames, anchorage to supporting 

walls, etc.) on the exterior façade of a school building should be 

designed to mitigate the hazardous effects of flying glass during 

an explosion event. In an effort to protect school occupants, designers should integrate the features of the glass, connection of 

the glass to the frame (bite), and anchoring of the frame to the 

building structure to achieve a “balanced design.” This means all 

the components should have compatible capacities and theoretically would all fail at the same pressure-pulse levels. In this way, 

the damage sequence and extent of damage are controlled. Table 

3-1 presents six GSA glazing protection levels based on how far 

glass fragments would enter a space and potentially injure its occupants. Figure 3-4 depicts how far glass fragments could enter a 

structure for each GSA performance condition. 
BUILDING DESIGN GUIDANCE AND SAFETY PLANS 3-13

Table 3-1: Glazing Protection Levels Based on Fragment Impact Locations1

Performance

Condition

Protection

Level

Hazard

Level

Description of Window

Glazing Response

1 Safe None Glazing does not break. No visible damage to glazing or frame.

2* Very High None Glazing cracks, but is retained by the frame. Dusting or very small 

fragments near sill or on floor acceptable. 

3a* High Very Low Glazing cracks. Fragments enter space and land on floor no more than 3.3 

feet from the window.

3b* High Low Glazing cracks. Fragments enter space and land on floor no more than 10 

feet from the window.

4* Medium Medium Glazing cracks. Fragments enter space and land on floor and impact a 

vertical witness panel at a distance of no more than 10 feet from the 

window at a height no greater than 2 feet above the floor.

5* Low High Glazing cracks and window system fails catastrophically. Fragments enter 

space, impacting a vertical witness panel at a distance of no more than 10 

feet from the window at a height greater than 2 feet above the floor.

* In conditions 2, 3a, 3b, 4 and 5, glazing fragments may be thrown to the outside of the protected space toward the detonation location.

1 From GSA PBS-PQ100.1, Facilities Standards for the Public Building Service, June 14, 1996

Figure 3-4 Side view of a test structure illustrating performance conditions of Table 3-2
3-14 BUILDING DESIGN GUIDANCE AND SAFETY PLANS 

The divide between performance conditions 3a and 3b can be 

equated to the “threshold of injury.” The divide between performance conditions 4 and 5 can be equated to the “threshold of 

lethality.” The GSA glazing performance conditions shown above 

correlate with the DoD levels of protection presented in Table 3-2.

Table 3-2: Correlation of GSA Glazing Performance Conditions and DoD Levels of Protection 

for New Buildings

GSA Glazing 

Performance 

Condition

Corresponding DoD Level of Protection for New 

Buildings

1 High

2 Medium

3a Low

3b/4 Very Low

5 Below Antiterrorism (AT) Standards

FEMA 426, Reference Manual to Mitigate Potential Terrorist Attacks 

Against Buildings, contains a detailed description of window system 

design considerations. Although not all windows in a school can 

be designed to resist the full forces from very large explosive blast 

events, hardened window systems can provide significant protection for students, faculty, and staff. Preferred systems include: 

thermally tempered glass with a security film installed on the 

interior surface and attached to the frame; laminated thermally 

tempered glass; laminated heat strengthened, or laminated annealed glass; and blast curtains. Glazing systems that do not 

provide any protection include: untreated monolithic annealed or 

heat-strengthened glass and wire glass. Figure 3-5 depicts an unprotected window after a large explosion.
BUILDING DESIGN GUIDANCE AND SAFETY PLANS 3-15

General Guidelines for Windows and Glazing. General guidelines 

for windows and glazing include the following:

❍ Do not place windows adjacent to doors because, if the 

windows are broken, the door can be unlocked.

❍ In schools requiring high security, minimize the number and 

size of windows in a façade. If possible, limit the amount of 

glazed area in building facades to 15 percent. The amount of 

blast entering a space is directly proportional to the amount 

of opening on the facade.

❍ Consider using burglary- and ballistic-resistant glazing in highrisk school areas.

❍ Consider using laminated glass in place of conventional glass.

❍ Consider window safety laminate (such as mylar) or another 

fragment retention film (FRF) over glazing (properly 

installed) to reduce fragmentation.

Figure 3-5 An unprotected window after a large explosion
3-16 BUILDING DESIGN GUIDANCE AND SAFETY PLANS 

❍ Consider placing guards, such as grills, screens, or meshwork, 

across window openings to protect against covert entry. Affix 

protective window guards firmly to the structure. Fire egress 

considerations must be judged against window guards.

❍ Position the operable section of a sliding window on the 

inside of the fixed section and secure it with a broomstick, 

metal rod, or similar device placed at the bottom of the track.

❍ Provide horizontal windows 6 feet above the finished floor to 

limit entry.

❍ Consider using steel window frames securely fastened or 

cement grouted to the surrounding structure.

❍ Minimize interior glazing in high-risk areas (e.g., lobbies, 

loading docks). 

Mullion and Wall Design. The frame members connecting adjoining windows are referred to as mullions. These members may 

be designed using a static approach when the breaking strength 

of the window glass is applied to the mullion, or a dynamic load 

may be applied using the peak pressure and impulse values. 

Although the static approach may seem easier, it often yields a 

design that is not practical, because the mullion can become very 

deep and heavy, driving up the weight and cost of the window 

system. In addition, it may not be consistent with the overall 

architectural objectives of the project. A dynamic approach is 

likely to provide a section that meets the design constraints of the 

project. To accomplish this, a single-degree-of-freedom solution 

is often used. The governing equation of motion may be solved 

using numerical methods. There are also charts available for linearly decaying loads that circumvent the need to solve differential 

equations. These charts only require that the fundamental period 

of the mullion (including the tributary area of the window glass), 

the ultimate resistance force of the mullion, the peak pressure, 

and the equivalent linear decay time are known.

Peak lateral response of the mullion is to be limited to a 2-degree support rotation. Also, the displacement ductility is to be limited to a 4-
BUILDING DESIGN GUIDANCE AND SAFETY PLANS 3-17

degree support rotation. As with frames, it is good engineering practice to limit the number of interlocking parts used for the mullion. 

3.3.4 Doors

Door assemblies include the door, its frame, and anchorage to the 

building. As part of a balanced school design approach, exterior 

doors in high-risk buildings should be designed to withstand the 

maximum dynamic pressure and duration of the load from the design threat explosive blast. Other general door considerations for 

these types of buildings are as follows:

❍ Provide hollow steel doors or steel-clad doors with steel 

frames. Ensure the strength of the latch and frame anchor 

equals that of the door and frame.

❍ Consider blast-resistant doors for schools considered to be at 

high risk.

❍ Permit normal entry/egress through a limited number of 

doors, if possible, while accommodating emergency egress.

❍ Ensure that exterior doors into inhabited areas open outward. 

In addition to facilitating egress, by doing so, the doors will 

seat into the door frames in response to an explosive blast, 

increasing the likelihood that the doors will not enter the 

school building as hazardous debris.

❍ Replace externally mounted locks and hasps with internally 

locking devices because the weakest part of most door 

assemblies is the latching component.

❍ Locate hinges on interior or use exterior security hinges to 

reduce their vulnerability. 

❍ Install emergency exit doors so that they facilitate only exiting 

movement.

❍ Consider using solid doors or walls as a backup for glass doors 

in foyers.

❍ Strengthen and harden the upright surfaces of a door jamb 

into which the door fits.
3-18 BUILDING DESIGN GUIDANCE AND SAFETY PLANS 

3.3.5 Roof System Design

Control access to school roofs to minimize the possibility of aggressors placing explosives or CBR agents there or otherwise 

threatening school occupants or critical infrastructure. Designers 

should consider the following:

❍ For new school buildings, eliminate all external roof access by 

providing access from internal stairways or ladders, such as in 

mechanical rooms.

❍ For existing school buildings, eliminate external access, where 

possible, or make roof access ladders removable, retractable, 

or lockable.

❍ Provide pitched roofs to allow deflection of explosives.

❍ Make school roof access hatches secure from intruders.

❍ Consider designing buildings with a sacrificial sloping roof 

that is above a protected ceiling (see Figure 3-6).

Figure 3-6 Sacrificial roof

3.4 MECHANICAL SYSTEMS

Mechanical systems design standards address limiting damage to 

critical infrastructure and protecting school building occupants 

against CBR threats. The primary goal of a mechanical system 
BUILDING DESIGN GUIDANCE AND SAFETY PLANS 3-19

after a terrorist attack should be to continue to operate key life 

safety systems for school occupants. School designers should be 

aware that during an interior bombing event, smoke removal and 

control are of paramount importance. They should consider the 

fact that, if window glazing is hardened, a blast may not blow out 

windows, and smoke may be trapped in the school building. In 

the event of a blast, the available smoke removal system may be essential to smoke removal, particularly in large, open spaces. This 

equipment should be located away from high-risk areas such as 

loading docks and garages. The system controls and power wiring 

to the equipment should be protected. The system should be connected to emergency power to provide smoke removal. Smoke 

removal equipment should be provided with standalone local control panels that can continue to individually function in the event 

the control wiring is severed from the main control system.

Designers should consider locating components in less vulnerable 

areas, limiting access to mechanical systems, and providing a reasonable amount of redundancy. Specific considerations include 

the following:

❍ Avoid mounting plumbing, electrical fixtures, or utility 

lines on the inside of exterior school walls. When this is 

unavoidable, mount fixtures on a separate wall at least 6 

inches from the exterior wall face.

❍ Avoid placing plumbing on the top of the roof deck of the 

school building.

❍ Avoid suspending plumbing fixtures and piping from the ceiling.

❍ Reduce the number of utility openings, manholes, tunnels, air 

conditioning ducts, filters, and access panels into the school 

structure.

❍ Protect school building operational control areas and utility 

feeds to lessen the negative effects of a blast.

❍ Design operational redundancies to survive all kinds of attacks.

❍ Use lockable systems for school utility openings and manholes 

where appropriate. Infrequently used utility covers/manholes 
3-20 BUILDING DESIGN GUIDANCE AND SAFETY PLANS 

can be tack-welded as an inexpensive alternative to locking 

tamper-resistant covers.

Key HVAC System Considerations. The following HVAC design 

measures should be considered to mitigate the risk of CBR threats 

against school buildings. A more detailed discussion of HVAC design considerations is contained in FEMA 426 Reference Manual to 

Mitigate Potential Terrorist Attacks Against Buildings and FEMA 427 

Primer for Design of Commercial Buildings to Mitigate Terrorist Attacks. 

HVAC protective actions are discussed in Chapter 5. 

❍ Place intakes at the highest practical level on the school 

building. For protection against malicious acts, the intakes 

should also be covered by screens so that objects cannot be 

tossed into the intakes or into air wells from the ground (see 

Figures 3-7, 3-8, and 3-9). Such screens should be sloped to 

allow thrown objects to roll or slide off the screen, away from 

the intake. Many existing school buildings have air intakes 

that are located at or below ground level. For those that have 

wall-mounted or below-grade intakes close to the building, the 

intakes can be elevated by constructing a plenum or external 

shaft over the intake (see Figure 3-10). 

SOURCE: CDC/NIOSH, PUBLICATION NO. 2002-139, GUIDANCE FOR PROTECTING BUILDING ENVIRONMENTS FROM AIRBORNE 

CHEMICAL, BIOLOGICAL, OR RADIOLOGICAL ATTACKS, MAY 2002.

Figure 3-7 Example of protecting outdoor air intakes
BUILDING DESIGN GUIDANCE AND SAFETY PLANS 3-21

Figure 3-8 Another example of protecting air intakes

SOURCE: CDC/NIOSH, PUBLICATION NO. 2002-139, GUIDANCE FOR PROTECTING BUILDING ENVIRONMENTS FROM AIRBORNE 

CHEMICAL, BIOLOGICAL, OR RADIOLOGICAL ATTACKS, MAY 2002.

SOURCE: CDC/NIOSH, PUBLICATION NO. 2002-139, 

GUIDANCE FOR PROTECTING BUILDING ENVIRONMENTS 

FROM AIRBORNE CHEMICAL, BIOLOGICAL, OR 

RADIOLOGICAL ATTACKS, MAY 2002.

Figure 3-9 

Example of elevated air intake
3-22 BUILDING DESIGN GUIDANCE AND SAFETY PLANS 

Figure 3-10 

Example of enclosing an 

existing vulnerable air 

intake

SOURCE: CDC/NIOSH, 

PUBLICATION NO. 2002-139, 

GUIDANCE FOR PROTECTING 

BUILDING ENVIRONMENTS 

FROM AIRBORNE CHEMICAL, 

BIOLOGICAL, OR RADIOLOGICAL 

ATTACKS, MAY 2002.

Ground-level Outdoor Air Intake

Raised-level Outdoor Air Intake

❍ Provide protection for existing school buildings with air 

intakes below grade, at ground level, or wall-mounted outside 

secure areas, with physical security measures (e.g., placing 

fencing, surveillance cameras, and motion detectors around 

the intakes to facilitate monitoring by security personnel). 

These measures can help prevent malicious acts, but are less 

effective than elevating the intakes, because ground level 

releases under certain conditions can enter the intakes from 

points outside the area fenced or under surveillance.
BUILDING DESIGN GUIDANCE AND SAFETY PLANS 3-23

❍ Maintain physical security on mechanical rooms to prevent 

the direct introduction of hazardous materials into the system 

of ducts that distributes air to the school building. This 

includes locking and controlling the access to all mechanical 

rooms containing HVAC equipment.

❍ Restrict access to school building operation systems by outside 

personnel. To deter tampering by outside maintenance 

personnel, a school staff member should escort these 

individuals throughout their service visit and should visually 

inspect their work before final acceptance of the service. 

Alternatively, schools can ensure the reliability of pre-screened 

service personnel from a trusted contractor.

❍ Restrict access to school building data. Information on building 

operations (including mechanical, electrical, vertical transport, 

fire and life safety, security system plans and schematics, and 

emergency operations procedures) should be controlled. 

❍ Isolate school lobbies, mailrooms, loading docks, and storage 

areas. Lobbies, mailrooms (includes various mail processing 

areas), loading docks, and other entry and storage areas 

should be physically isolated from the rest of the building. 

These are areas where bulk quantities of CBR agents are likely 

to enter a school building. 

❍ Consider “shelter-in-place” rooms or areas in schools, where 

people can stay in the event of an outdoor release. The goal 

is to create areas where outdoor air infiltration is very low. 

Usually such rooms will be in the inner part of the school 

in an area with no exterior windows if possible. The rooms 

should have doors that are fairly effective at preventing 

airflow and should contain staging supplies such as duct tape 

and plastic to help further seal the areas from the hallways. 

Typically, restrooms are a bad choice, because they have 

exhaust ducts that lead directly to the outside. Opening and 

closing a conventional hinged door can pump large amounts 

of air into the room; if practical, replace the door with a code 
3-24 BUILDING DESIGN GUIDANCE AND SAFETY PLANS 

compliant sliding door to reduce this effect. Additionally, 

it may be possible to provide purified air to the safe area 

through modifications to the HVAC system. For more 

information, see Chapters 5 and 6.

❍ Ducted returns offer limited access points to introduce a 

CBR agent. The return vents can be placed in conspicuous 

locations throughout a school, reducing the risk of an agent 

being secretly introduced into the return system. Non-ducted 

return air systems commonly use hallways or spaces above 

suspended ceilings as a return-air path or plenum. CBR agents 

introduced at any location above the suspended ceiling in 

a ceiling plenum return system will probably migrate back 

to the HVAC unit and be redistributed to occupied areas. 

Schools should be designed to minimize mixing between 

air-handling zones, which can be partially accomplished by 

limiting shared returns. 

3.5 ELECTRICAL SYSTEMS

The major security functions of the electrical system are to maintain 

power to essential school services, especially those required for life 

safety and evacuation. When designing a school building, architects 

and engineers should consider providing lighting and surveillance 

to deter criminal activities, and provide emergency communications. 

They should also consider the following recommendations:

❍ Emergency and normal electric panels, conduits, and 

switchgear should be installed separately, at different 

locations, and as far apart as possible. Electric distribution 

should also run at separate locations.

❍ Emergency generators should be located away from loading 

docks, entrances, and parking. More secure locations include 

the roof, protected grade level, and protected interior areas. 

❍ Main fuel storage for generators should be located away from 

loading docks, entrances, and parking. Access should be 

restricted and protected (e.g., locks on caps and seals).
BUILDING DESIGN GUIDANCE AND SAFETY PLANS 3-25

❍ Fuel tanks should be mounted near the generator, given 

the same protection as the generator, and sized to store an 

appropriate amount of fuel. A battery and/or UPS could be a 

viable alternative for a smaller school.

❍ Conduits and lines should be installed outside to allow a 

trailer-mounted generator to connect to the school’s electrical 

system. If tertiary power is required, other methods include 

generators and feeders from alternative substations.

❍ Emergency power should be provided for emergency lighting 

in school restrooms, egress routes, and any meeting room 

without windows.

❍ School building access points should be illuminated to aid in 

threat detection. 

❍ Self-contained battery lighting should be provided in 

stairwells and for exit signs.

❍ Suspending electrical conduits from the ceiling should be 

avoided.

❍ Adequate lighting of perimeters and parking areas should be 

provided to aid in visual surveillance and to support the use of 

CCTV.

3.6 FIRE PROTECTION SYSTEMS

The fire protection system inside the school building should 

maintain life safety protection after an incident and allow for safe 

evacuation of the building when appropriate. Although fire protection systems are designed to perform well during fires, they are 

not traditionally designed to survive bomb blasts. Fire protection 

system considerations include the following: 

❍ A school’s fire protection water system should be protected 

from single-point failure in case of a blast event. The 

incoming line should be encased, buried, or located 50 feet 

away from high-risk areas. The interior mains should be 

looped and sectionalized.
3-26 BUILDING DESIGN GUIDANCE AND SAFETY PLANS 

❍ To increase the reliability of the fire protection system, a dual 

pump arrangement should be considered, with one electric 

pump and one diesel pump. The pumps should be located 

away from each other.

❍ All school security locking arrangements on doors used for egress 

must comply with requirements of NFPA 101, Life Safety Code.

3.7 COMMUNICATIONS SYSTEMS

Designers should consider the following:

❍ Redundant communications. The school should have a 

second telephone service to maintain communications in 

case of an incident. A base radio communications system with 

antenna should be installed in the stairwell, and portable sets 

distributed on floors. This is the preferred alternative.

❍ Radio telemetry. Distributed antennas could be located 

throughout the school facility if required for emergency 

communications through wireless transmission of data.

❍ Alarm and information systems. Alarm and information systems 

should not be collected and mounted in a single conduit, or 

even collocated. Circuits to various parts of the school building 

should be installed in at least two directions and/or risers. 

Low voltage signal and control copper conductors should not 

share conduits with high voltage power conductors. Fiber-optic 

conductors are generally preferred over copper.

❍ Empty conduits. Empty conduits and power outlets can be provided for possible future installation of security control equipment.

❍ Mass notification. All inhabited school buildings should have 

a timely means to notify occupants of threats and instruct 

them what to do in response to those threats. School buildings 

should have a capability to provide real-time notification of 

building occupants and people in the immediate vicinity of 

the building during emergency situations. The information 
BUILDING DESIGN GUIDANCE AND SAFETY PLANS 3-27

relayed should be specific enough to determine the 

appropriate response actions.

3.8 PHYSICAL SECURITY SYSTEMS

Physical security is defined as that part of security concerned with 

physical measures designed to safeguard people and to prevent 

unauthorized access to equipment, certain areas of the school 

building, and key documents. These days, all security operations 

face new and complex physical security challenges across the full 

spectrum of operations.

Although security technologies are not the answer to all school 

security problems, if applied appropriately, they can enhance 

security, free up administrators for more appropriate work, and 

sometimes can save money. At a non-educational building, a typical approach to physical security is:

For example, if someone is breaking into a school facility, it is 

necessary to have a means of detection so that information can be 

provided to appropriate authorities. Next, the intruder must be 

delayed as long as possible so that the response force may arrive. 

Finally, someone, such as the police, must respond to the incident 

to catch the intruder. For a school, the National Institute for Justice2

 has recommended expanding this model as shown below:

 2 National Institute of Justice Research Report NCJ 178265, The Appropriate and Effective Use of Security Technologies in U.S. Schools,

September 1999.
3-28 BUILDING DESIGN GUIDANCE AND SAFETY PLANS 

This educational approach emphasizes deterrence by instituting 

measures both before and after an event to convince perpetrators 

not to do whatever they are considering. Although, the efficacy of 

deterrence for high-risk terrorist tactics is questionable, schools 

have a broad spectrum of threats to consider with any physical security system. Schools are also unique in that they generally have 

the authority and opportunity to establish consequences for incidents that involve students and occur on school grounds. Figure 

3-11 depicts some considerations for the design of a school security 

system and Figure 3-12 shows examples of physical security devices.

For schools requiring greater security, some general measures are 

contained in the National Institute of Justice Research Report NCJ 

178265, The Appropriate and Effective Use of Security Technologies in 

U.S. Schools, September 1999.

Figure 3-11 Considerations for the design of a new security system

SOURCE: NATIONAL INSTITUTE OF JUSTICE RESEARCH REPORT NCJ 178265, THE APPROPRIATE AND EFFECTIVE USE OF SECURITY 

TECHNOLOGIES IN U.S. SCHOOLS, SEPTEMBER 1999. 
BUILDING DESIGN GUIDANCE AND SAFETY PLANS 3-29

Obviously, when considering any physical security measure for a 

school, it is important to balance its use with the risk of creating a 

“bunker” or “prison” atmosphere that is not conducive to learning. 

The measures recommended in this chapter should be applied 

judiciously and in concert with the threat assessment depicted in 

Chapter 1, and also with any risk perceived by school administrators.

3.9 SUMMARY OF BUILDING ENVELOPE 

MITIGATION MEASURES

A general spectrum of building envelope mitigation measures 

ranging from the least protection, cost, and effort going to the 

greatest protection, cost, and effort is provided below. Detailed 

discussions of individual measures can be found earlier in this 

chapter. Please note this is a nominal ranking of mitigation 

measures. In practice, the effectiveness and cost of individual mitigation measures may deviate from this example based on specific 

applications.

Figure 3-12 Physical security devices
3-30 BUILDING DESIGN GUIDANCE AND SAFETY PLANS 

• Ensure that all school exterior doors into inhabited areas open outward. Ensure emergency exit doors 

only facilitate exiting.

• Secure school roof access hatches from the interior. Prevent public access to building roofs.

• Restrict access to school building operation systems.

• Conduct periodic training of school HVAC maintenance and operation staff.

• Evaluate HVAC control options.

• Install empty conduits for future school security control equipment during initial construction or major 

renovation.

• Do not mount plumbing, electrical fixtures, or utility lines on the inside of exterior walls.

• Minimize interior glazing near high-risk a reas.

• Establish school emergency plans, policies, and procedures.

• Establish written plans for school evacuation and sheltering in place.

• Illuminate school access points.

• Restrict access to school building information.

• Secure HVAC intakes and mechanical rooms.

• Limit the number of doors used for normal entry/egress.

• Lock all utility access openings.

• Provide emergency power for emergency lighting in school restrooms, egress routes, and any meeting 

room without windows.

• Install an internal public address system.

• Stagger interior doors and offset interior and exterior doors.

• Eliminate hiding places.

• Install a second and separate telephone service.

• Install radio telemetry distributed antennas throughout the facility. 

• Use a badge identification system for school access.

• Install a CCTV surveillance system in areas where needed.

• Install an electronic security alarm system in areas where needed.

• Install rapid response and isolation features into school HVAC systems. 

• Use interior barriers to differentiate levels of security.

• Avoid eaves and overhangs or harden to withstand blast effects.

• Locate utility systems away from likely areas of potential attack.

• Install call buttons at key public contact areas.

• Install emergency and normal electric equipment at different locations.

• Avoid exposed structural elements.

Continued on next page
BUILDING DESIGN GUIDANCE AND SAFETY PLANS 3-31

• Reinforce foyer walls.

• Use architectural features to deny contact with exposed primary vertical load members.

• Isolate school lobbies, mailrooms, loading docks, and storage areas.

• Locate stairwells remotely. Do not discharge stairs into lobbies, parking, or loading areas.

• Elevate school HVAC fresh-air intakes.

• Create “shelter-in-place” rooms or areas.

• Separate HVAC zones. Eliminate leaks and increase school building air tightness.

• Install blast-resistant doors or steel doors with steel frames. 

• Physically separate unsecured areas from the main school building.

• Install HVAC exhausting and purging systems.

• Connect interior non-load bearing walls to structure with non-rigid connections.

• Use structural design techniques to resist progressive collapse of school buildings.

• Treat exterior shear walls as primary structures.

• Orient glazing perpendicular to the primary façade facing uncontrolled vehicle approaches.

• Use reinforced concrete wall systems in lieu of masonry or curtain walls.

• Ensure active fire system is protected from single-point failure in case of a blast event.

• Establish school’s ground floor elevation 4 feet above grade.

• Avoid re-entrant corners on the school building exterior.

• Issue CBR personal protective equipment.

• Design exterior walls to resist blast. 

• Design school facilities with a sacrificial sloping roof above a protected ceiling.

• Upgrade glazing - laminated glass, safety laminates, FRF, etc.

• Install a 24-hour on-site monitoring center.

• Install HVAC filtering and pressurization.

• Install HVAC CBR real-time monitoring detectors.
3-32 BUILDING DESIGN GUIDANCE AND SAFETY PLANS 

3.10 RECOMMENDATIONS BASED ON THE 

HOMELAND SECURITY ADVISORY 

SYSTEM 

Table 3-3 presents recommendations for safety/security measures 

linked to the DHS Threat Advisory Level. Chapter 6 of the U.S. Department of Education (DOE) Practical Information on Crisis Planning: 

A Guide for Schools and Communities contains similar recommendations.

Table 3-3: Safety/Security Recommendations

DHS Threat 

Advisory Level Recommended Actions

Green – Low Risk

❍		Develop school written emergency plans

❍		Coordinate emergency plans with local, state, and federal plans

❍		Ensure selected staff members take a Red Cross cardiopulmonary resuscitation (CPR)/automated 

external defibrillator (AED) and first aid course

❍		Develop emergency communications plan and lists

❍		Conduct crisis management and communications training for all employees

❍		Disseminate emergency procedures and plans to parents

❍		Develop and implement visitor control procedures

❍		Obtain emergency supplies and equipment

❍		Obtain copies of Terrorism: Preparing for the Unexpected brochure from the local Red Cross chapter

Blue – Guarded

❍		Complete recommended actions at lower level

❍		Review and update emergency plans

❍		Upgrade to appropriate visitor control procedures

❍		Review and update emergency communication plan and lists

❍		Inventory and restock emergency supplies

❍		Conduct safety training /emergency drills following the school’s written emergency plan

Yellow - Elevated

❍		Complete recommended actions at lower level

❍		Be alert to suspicious activity and report it to the proper authorities

❍		Assess increased risk with public safety officials

❍		Reassess school security measures

❍		Verify that emergency supplies are stocked and ready

❍		Review field trip decisions

❍		Update employee emergency call lists and review callback process with employees

❍		Test alternate communications capabilities

❍		Increase communications with parents and community via web site and e-mail distributions

❍		Distribute copies of Terrorism: Preparing for the Unexpected brochure from the local Red Cross 

chapter and send it home with students in grades K-12, faculty, and staff
BUILDING DESIGN GUIDANCE AND SAFETY PLANS 3-33

3.11 SCHOOL SAFETY EMERGENCY 

MANAGEMENT PLAN

The DHS has designated the DOE as the lead agency for security 

related to schools. The DOE has published a guide, Practical Information on Crisis Planning: A Guide for Schools and Communities, May 

2003, that is intended to give schools, districts, and communities 

the critical concepts and components of good crisis planning, 

stimulate thinking about crisis preparedness process, and provide 

examples of promising practices. Additional information is also 

available from the National Advisory Committee on Children and 

Terrorism (NACCT).

Orange - High

❍		Complete recommended actions at lower level

❍		Consider canceling outside activities

❍		Prepare to handle inquiries from anxious parents and media

❍		Review and implement increased security measures

• Limit parking near school buildings

• Restrict visitor access

❍		Discuss children’s fears concerning possible terrorist attacks

❍		Review sporting event and extracurricular activity decisions

❍		Place school and district crisis response teams on standby alert status

Red - Severe

❍		Complete recommended actions at lower level

❍		Follow local and/or Federal Government instructions

❍		Coordinate with local and state officials to consider school openings and closings

❍		Listen to radio/TV for current information/instructions

❍		Review and implement increased security measures

• Further limiting parking to increase stand-off

• Posting/increasing security staff 

❍		Activate command and support centers if appropriate

❍		Continue staff, parent, and community communications

❍		Coordinate parent-child reunification process, if necessary

❍		Ensure mental health counselors are available for students, faculty, and staff

Table 3-3: Safety/Security Recommendations (continued)

DHS Threat 

Advisory Level Recommended Actions
3-34 BUILDING DESIGN GUIDANCE AND SAFETY PLANS 

The DOE recommends each school crisis plan address four major 

areas: mitigation/prevention, preparedness, response, and recovery. 

❍ Mitigation/Prevention:

• Conduct an assessment of each school building. Identify 

those factors that put the building, students, faculty, and 

staff at greater risk, such as proximity to rail tracks that 

regularly transport hazardous materials or facilities that 

produce highly toxic material or propane gas tanks, and 

develop a plan for reducing the risk. This can include 

plans to evacuate students away from these areas in times of 

crisis and to reposition propane tanks or other hazardous 

materials away from school buildings.

• Work with businesses and factories in close proximity to the 

school to ensure that the school’s crisis plan is coordinated 

with their crisis plans. 

• Ensure that a process is in place for controlling access and 

egress to the school. Require all persons who do not have 

authority to be in the school to sign in.

• Review traffic patterns, and where possible, keep cars, buses, 

and trucks away from school buildings.

• Review landscaping, and ensure that buildings are not 

obscured by overgrowth of bushes or shrubs where 

contraband can be placed or persons can hide. 

❍ Preparedness:

• Have site plans for each school building readily available 

and ensure they are shared with first responders and 

agencies responsible for emergency preparedness.

• Ensure there are multiple evacuation routes and rallying 

points. First or second evacuation site options may be 

blocked or unavailable at the time of the crisis.

• Practice responding to crisis on a regular basis. 
BUILDING DESIGN GUIDANCE AND SAFETY PLANS 3-35

• Ensure a process is established for communicating during a 

crisis. 

• Inspect equipment to ensure it operates during crisis situations. 

• Have a plan for discharging students. Remember that, 

during a crisis, many parents and guardians may not be 

able to get to the school to pick up their child. Make sure 

every student has a secondary contact person and contact 

information readily available.

• Have a plan for communicating information to parents and 

for quelling rumors. Cultivate relationships with the media 

ahead of time, and identify a Public Information Officer 

(PIO) to communicate with the media and the community 

during a crisis. 

• Work with law enforcement officials and emergency 

preparedness agencies on a strategy for sharing key parts of 

the school crisis plans.

❍ Response:

• Identify the type of crisis that is occurring and determine 

the appropriate response.

• Develop a command structure for responding to a 

crisis. The roles and responsibilities for educators, law 

enforcement and fire officials, and other first responders in 

responding to different types of crisis need to be developed, 

coordinated, reviewed, and approved. 

• Maintain communications among all relevant staff.

❍ Recovery:

• Return to the business of teaching and learning as soon as 

possible. 

• Identify and approve a team of credentialed mental health 

workers to provide mental health services to faculty and 

students after a crisis. Understand that recovery takes place 

over time and that the services of this team may be needed 

over an extended time period. 
3-36 BUILDING DESIGN GUIDANCE AND SAFETY PLANS 

• Ensure that the team is adequately trained.

• The plan needs to include notification of parents on actions 

that the school intends to take to help students recover 

from the crisis.

3.12 EMERGENCY PLANS AND TRAINING

Every school should have a school safety emergency management plan developed in partnership with public safety agencies, 

including law enforcement, fire, public health, mental health and 

local emergency preparedness agencies. The plan should address 

fire, and natural and manmade disasters. A school’s plan should 

be tailored to address the unique circumstances and needs of the 

individual school, and should be coordinated and integrated with 

community plans and the plans of local emergency preparedness 

agencies. 

These plans should also consider CBR attack scenarios and the associated procedures for communicating instructions to building 

occupants, identifying suitable shelter-in-place areas (if they exist), 

identifying appropriate use and selection of personal protective equipment (i.e., clothing, gloves, respirators) and directing 

emergency evacuations. Individuals developing emergency plans 

and procedures should recognize that there are fundamental differences between chemical, biological, and radiological agents. 

In general, chemical agents will show a rapid onset of symptoms, 

while the response to biological and radiological agents will be delayed. Issues such as designated areas and procedures for chemical 

storage, HVAC control or shutdown, and communications with 

school occupants and emergency responders, should all be addressed. The plans should be as comprehensive as possible, but, 

as described earlier, protected by limited and controlled access. 

When appropriately developed, these plans, policies, and procedures can have a major impact upon school occupant survivability 

in the event of a CBR release.
BUILDING DESIGN GUIDANCE AND SAFETY PLANS 3-37

Staff training, particularly for those with specific responsibilities during an event, is essential and should cover both internal 

and external events. Holding regularly scheduled practice drills, 

similar to the common fire drill, allows for plan testing, as well 

as student and key staff rehearsal of the plan, and increases the 

likelihood for success in an actual event. School officials should 

ensure that training is provided to staff that operate and maintain the school’s HVAC system. This training should include the 

procedures to be followed in the event of a suspected CBR agent 

release. Development of current, accurate HVAC diagrams and 

HVAC system labeling protocols should be addressed. These documents can be of great value in the event of a CBR release.

EXPLOSIVE BLAST 4

EXPLOSIVE BLAST 4-1

T his chapter discusses blast effects, potential school damage, 

injuries, levels of protection, stand-off distance, and predicting blast effects. Specific blast design concerns and 

mitigation measures are 

discussed in Chapters 2 and 

3. Explosive events have historically been a favorite tactic 

of terrorists for a variety of 

reasons and this is likely to 

continue into the future. The 

DoD, GSA, and DOS have 

considerable experience with 

blast effects and blast mitigation. However, many architects 

and building designers do not 

have such experience. For 

additional information on explosive blast, see FEMA 426, 

Reference Manual to Mitigate 

Potential Terrorist Attacks Against 

Buildings, and FEMA 427,

Primer for Design of Commercial 

Buildings to Mitigate Terrorist 

Attacks. See sidebar for important reference material on 

explosive blast.

4.1 BLAST EFFECTS

An explosion is an extremely rapid release of energy in the form 

of light, heat, sound, and a shock wave. A shock wave consists of 

highly compressed air traveling radially outward from the source 

at supersonic velocities. As the shock wave expands, pressures decrease rapidly (with the cube of the distance) and, when it meets 

a surface that is in line-of-sight of the explosion, it is reflected and 

amplified by a factor of up to thirteen. Pressures also decay rapThe following additional references are recommended:

❍ Air Force Engineering and Services Center. Protective Construction Design Manual, 

ESL-TR-87-57. Prepared for Engineering and Services Laboratory, Tyndall Air 

Force Base, FL. (1989).

❍ U.S. Department of the Army. Security Engineering, TM 5-853 and Air Force 

AFMAN 32-1071, Volumes 1, 2, 3, and 4. Washington, DC, Departments of the 

Army and Air Force. (1994).

❍ U.S. Department of the Army. Structures to Resist the Effects of Accidental 

Explosions, Army TM 5-1300, Navy NAVFAC P-397, AFR 88-2. Washington, DC, 

Departments of the Army, Navy, and Air Force. (1990).

❍ U.S. Department of Energy. A Manual for the Prediction of Blast and Fragment 

Loading on Structures, DOE/TIC 11268. Washington, DC, Headquarters, U.S. 

Department of Energy. (1992).

❍ U.S. General Services Administration. GSA Security Reference Manual: Part 3 Blast 

Design and Assessment Guidelines. (2001).

❍ Biggs, John M. Introduction to Structural Dynamics. McGraw-Hill. (1964).

❍ The Institute of Structural Engineers. The Structural Engineer’s Response to 

Explosive Damage. SETO, Ltd., 11 Upper Belgrave Street, London SW1X8BH. 

(1995).

❍ Mays, G.S. and Smith, P.D. Blast Effects on Buildings: Design of Buildings to 

Optimize Resistance to Blast Loading. Thomas Telford Publications, 1 Heron Quay, 

London E14 4JD. (1995).

❍ National Research Council. Protecting Buildings from Bomb Damage. National 

Academy Press. (1995).
4-2 EXPLOSIVE BLAST 

idly over time (i.e., exponentially) and have a very brief span of 

existence, measured typically in thousandths of a second, or milliseconds. Diffraction effects, caused by corners of a building, may 

act to confine the air-blast, prolonging its duration. Late in the 

explosive event, the shock wave becomes negative, creating suction. Behind the shock wave, where a vacuum has been created, 

air rushes in, creating a powerful wind or drag pressure on all surfaces of the building. This wind picks up and carries flying debris 

in the vicinity of the detonation. In an external explosion, a portion of the energy is also imparted to the ground, creating a crater 

and generating a ground shock wave analogous to a high-intensity, 

short-duration earthquake.

In the context of other hazards (e.g., earthquakes, winds, or floods), 

an explosive attack has the following distinguishing features:

❍ The intensity of the pressures acting on a targeted building 

can be several orders of magnitude greater than these other 

hazards. It is not uncommon for the peak pressure to be in 

excess of 100 pounds per square inch (psi) on a building in an 

urban setting for a vehicle weapon parked along the curb. At 

these pressure levels, major damages and failure are expected.

❍ Explosive pressures decay extremely rapidly with distance 

from the source. Therefore, the damages on the side of the 

building facing the explosion may be significantly more severe 

than on the opposite side. As a consequence, direct air-blast 

damages tend to cause more localized damage.

❍ The duration of the event is very short, measured in 

thousandths of a second, or milliseconds. This differs from 

earthquakes and wind gusts, which are measured in seconds, 

or sustained wind or flood situations, which may be measured 

in hours. Because of this, the mass of the structure has a 

strong mitigating effect on the response because it takes time 

to mobilize the mass of the structure. By the time the mass is 

mobilized, the loading is gone, thus mitigating the response. 

This is the opposite of earthquakes, whose imparted forces are 

roughly in the same timeframe as the response of the building 

mass, causing a resonance effect that can worsen the damage.
EXPLOSIVE BLAST 4-3

4.1.1 Building Damage

The extent and severity of damage and injuries in an explosive 

event cannot be predicted with perfect certainty. Past events show 

that the unique specifics of the failure sequence for a building significantly affect the level of damage. Despite these uncertainties, it 

is possible to give some general indications of the overall level of 

damage and injuries to be expected in an explosive event, based 

on the size of the explosion, distance from the event, and assumptions about the construction of the building. 

Damage due to the air-blast shock wave may be divided into direct 

air-blast effects and progressive collapse. Direct air-blast effects 

are damage caused by the high-intensity pressures of the air-blast 

close in to the explosion and may induce the localized failure of 

exterior walls, windows, floor systems, columns, and girders. Progressive collapse is discussed in Section 3.2.

The air-blast shock wave is the primary damage mechanism in an 

explosion. The pressures it exerts on building surfaces may be 

several orders of magnitude greater than the loads for which the 

building is designed. The shock wave also acts in directions that 

the building may not have been designed for, such as upward on 

the floor system. In terms of sequence of response, the air-blast 

first impinges on the weakest point in the vicinity of the device 

closest to the explosion, typically the exterior envelope of the 

building. The explosion pushes on the exterior walls at the lower 

stories and may cause wall failure and window breakage. As the 

shock wave continues to expand, it enters the structure, pushing 

both upward and downward on the floors (see Figure 4-1).

Floor failure is common in large-scale vehicle-delivered explosive 

attacks, because floor slabs typically have a large surface area for 

the pressure to act on and a comparably small thickness. In terms 

of the timing of events, the building is engulfed by the shockwave 

and direct air-blast damage occurs within tens to hundreds of milliseconds from the time of detonation. If progressive collapse is 

initiated, it typically occurs within seconds.
4-4 EXPLOSIVE BLAST 

Figure 4-1 Blast pressure effects on a structure

Glass is often the weakest part of a building, breaking at low pressures compared to other components such as the floors, walls, 

or columns. Past incidents have shown that glass breakage may 

extend for miles in large external explosions. High-velocity glass 
EXPLOSIVE BLAST 4-5

fragments have been shown to be a major contributor to injuries 

in such incidents. For incidents within downtown city areas, falling 

glass poses a major hazard to passersby on the sidewalks below and 

prolongs post-incident rescue and cleanup efforts by leaving tons 

of glass debris on the street. Specific glazing design considerations 

are discussed in Chapter 3.

4.1.2 Casualties and Injuries

Blast can cause significant casualties. During the bombing of the 

Murrah Federal Building, 168 people were killed. Severity and 

type of injury patterns incurred in explosive events may be related to the level of structural damage. The high pressure of the 

air-blast that enters through broken windows can cause eardrum 

damage and lung collapse. As the air-blast damages the building 

components in its path, missiles are generated that cause impact 

injuries. Airborne glass fragments typically cause penetration or 

laceration-type injuries. Larger fragments may cause non-penetrating, or blunt trauma, injuries. Finally, the air-blast pressures 

can cause occupants to be bodily thrown against objects or to fall. 

Lacerations due to high-velocity flying glass fragments have been 

responsible for a significant portion of the injuries received in explosion incidents. In the bombing of the Murrah Federal Building 

in Oklahoma City, for instance, 40 percent of the survivors in the 

building cited glass as contributing to their injuries. Within nearby 

buildings, laceration estimates ranged from 25 percent to 30 percent.

4.1.3 Levels of Protection

The amount of explosive and the resulting blast dictate the level 

of protection required to prevent a building from collapsing or 

minimize injuries and deaths. Table 4-1 shows how the DoD correlates levels of protection with potential damage and expected 

injuries. The GSA and the Interagency Security Committee (ISC) 

also use the level of protection concept. However, wherein DoD 

has five levels, they have established four levels of protection. The 

GSA and ISC levels of protection can be found in GSA PBS-P100, 

Facilities Standards for the Public Buildings Service, November 2000, 

Section 8.6.
4-6 EXPLOSIVE BLAST 

Table 4-1: DoD Minimum Antiterrorism (AT) Standards for New Buildings

Level of 

Protection Potential Structural Damage Potential Door and Glazing Hazards Potential Injury

Below AT 

standards

Severely damaged – frame collapse/massive 

destruction. Little left standing. 

Doors and windows fail and result in 

lethal hazards 

Majority of personnel 

suffer fatalities. 

Very Low

Heavily damaged – onset of structural 

collapse. Major deformation of primary 

and secondary structural members, but 

progressive collapse is unlikely. Collapse of 

non-structural elements. 

Glazing will break and is likely to be 

propelled into the building, resulting 

in serious glazing fragment injuries, 

but fragments will be reduced. 

Doors may be propelled into rooms, 

presenting serious hazards. 

Majority of personnel 

suffer serious injuries. 

There are likely to be 

a limited number (10 

percent to 25 percent) 

of fatalities. 

Low

Damaged – unrepairable. Major deformation 

of non-structural elements and secondary 

structural members and minor deformation of 

primary structural members, but progressive 

collapse is unlikely. 

Glazing will break, but fall within 

1 meter of the wall or otherwise 

not present a significant fragment 

hazard. Doors may fail, but they 

will rebound out of their frames, 

presenting minimal hazards. 

Majority of personnel 

suffer significant 

injuries. There may be 

a few (<10 percent) 

fatalities. 

Medium

Damaged – repairable. Minor deformations 

of non-structural elements and secondary 

structural members and no permanent 

deformation in primary structural members. 

Glazing will break, but will remain 

in the window frame. Doors will stay 

in frames, but will not be reusable. 

Some minor injuries, 

but fatalities are 

unlikely. 

High

Superficially damaged. No permanent 

deformation of primary and secondary 

structural members or non-structural 

elements. 

Glazing will not break. Doors will be 

reusable. 

Only superficial injuries 

are likely. 

SOURCE: THE DoD UNIFIED FACILITIES CRITERIA (UFC), DoD MINIMUM ANTITERRORISM STANDARDS FOR BUILDINGS, UFC 4-010-01, 31 JULY 2002

The levels of protection above can roughly be correlated for 

conventional construction without any blast hardening to the following incident pressures as shown in Table 4-2.

Table 4-2: Correlation of DoD Level of Protection to Incident Pressure

Level of Protection Incident Pressure (psi)

High 1.1

Medium 1.8

Low 2.3
EXPLOSIVE BLAST 4-7

Figure 4-2 shows an example of a range-to-effect chart that indicates the distance or stand-off to which a given size bomb will 

produce a given effect (see Section 4.2). This type of chart can 

be used to display the blast response of a building component 

or window at different levels of protection. It can also be used to 

consolidate all building response information to assess needed actions if the threat weapon-yield changes. For example, an amount 

of explosives are stolen and indications are that they may be used 

against a specific building. A building-specific range-to-effect 

chart will allow quick determination of the needed stand-off for 

the amount of explosives in question, once the explosive weight 

is converted to trinitrotoluene (TNT) equivalence. Given an explosive weight and a stand-off distance, Figure 4-2 can be used to 

predict damage for nominal building construction.

For design purposes, large scale truck bombs typically contain 

10,000 pounds or more of TNT equivalent, depending on the size 

and capacity of the vehicle used to deliver the weapon. Vehicle 

bombs that utilize vans down to small sedans typically contain 4,000 

to 500 pounds of TNT equivalent, respectively. A briefcase bomb 

is approximately 50 pounds, and a pipe bomb is generally in the 

range of 5 pounds of TNT equivalent. Research performed as part 

of the threat assessment process should identify bomb sizes used in 

the locality or region. Security consultants have valuable information that may be used to evaluate the range of likely charge weights.

Figures 4-3 and 4-4 show blast effects predictions for a high school 

based on a typical car bomb, and a typical large truck bomb detonated in the school’s parking lot, respectively. A computer-based 

GIS was used to analyze the school’s vehicular access and circulation pattern to determine a reasonable detonation point for a 

vehicle bomb. Structural blast analysis was then performed using 

nominal explosive weights and a nominal school structure. The 

results are shown in Figures 4-3 and 4-4. The red ring indicates 

the area in which structural damage is predicted. The orange and 

yellow rings indicate predictions for lethal injuries and severe injuries from glass, respectively. Please note that nominal inputs were 

used in this analysis and they are not a predictive examination.
4-8 EXPLOSIVE BLAST 

SOURCE: DEFENSE THREAT REDUCTION AGENCY

Figure 4-2 Explosives environments - blast range to effects
EXPLOSIVE BLAST 4-9

Figure 4-3 Blast analysis of a high school for a typical car bomb detonated in the school’s parking lot

Figure 4-4 Blast analysis of a high school for a typical large truck bomb detonated in the school’s 

parking lot
4-10 EXPLOSIVE BLAST 

In the case of a stationary vehicle bomb, knowing the size of the 

bomb (TNT equivalent in weight), its distance from the structure, 

how the structure is put together, and the materials used for walls, 

framing, and glazing allows the designer to determine the level 

of damage that will occur and the level of protection achieved. 

Whether an existing building or a new construction, the designer 

can then select mitigation measures as presented in this chapter 

and Chapters 2 and 3 to achieve the level of protection desired.

4.2 STAND-OFF DISTANCE AND THE EFFECTS 

OF BLAST 

Energy from a blast decreases rapidly over distance. In general, 

the cost to provide asset protection will decrease as the distance 

between an asset and a threat increases, as shown in Figure 4-5. 

However, increasing stand-off also requires more land and more 

perimeter to secure with barriers, resulting in an increased cost 

not reflected in Figure 4-5. As stand-off increases, blast loads generated by an explosion decrease and the amount of hardening 

necessary to provide the required level of protection decreases. 

Figure 4-5 Relationship of cost to stand-off distance

SOURCE: U.S. AIR FORCE, INSTALLATION FORCE PROTECTION GUIDE
EXPLOSIVE BLAST 4-11

The critical location of the weapon is a function of the site, the 

building layout, and the security measures in place. For vehicle 

bombs, the critical locations are considered to be at the closest 

point that a vehicle can approach on each side, assuming that all 

security measures are in place. Typically this is a vehicle parked 

along the curb directly outside the building, or at the entry control point where inspection takes place. For internal weapons, 

location is dictated by the areas of the building that are publicly 

accessible (e.g., lobbies, corridors, auditoriums, cafeterias, or 

gymnasiums). Range or stand-off is measured from the center of 

gravity of the charge located in the vehicle or other container to 

the building component under consideration. 

Defining appropriate stand-off distance for a given building component to resist explosive blast effects is difficult. Often in urban 

settings, it is either not possible or practical to obtain appropriate 

stand-off distance. Adding to the difficulty is the fact that defining 

appropriate stand-off distance requires a prediction of the explosive weight of the weapon. In the case of terrorism, this is tenuous 

at best.

The DoD prescribes minimum stand-off distances based on the 

required level of protection. Where minimum stand-off distances 

are met, conventional construction techniques can be used with 

some modifications. In cases where the minimum stand-off cannot 

be achieved, the building must be hardened to achieve the required level of protection (see the DoD UFC – DoD Minimum 

Antiterrorism Standards for Buildings, UFC 4-010-01, 31 July 2002).

The first step in predicting blast effects on a building is to predict 

blast loads on the structure. Because blast pressure pulse varies 

based on stand-off distance, angle of incidence, and reflected 

pressure over the exterior of the building, the blast load predictions can be very complex. Consultants may use sophisticated 

methods such as Computational Fluid Dynamics (CFD) computer 

programs to predict blast loads. These complex programs require 

special equipment and training to run.
4-12 EXPLOSIVE BLAST 

In most cases, especially for design purposes, more simplified 

methods may be used by blast consultants to predict blast loads. 

Tables of pre-determined values (see GSA Security Reference Manual: 

Part 3 – Blast Design & Assessment Guidelines, July 31, 2001) or computer programs may be used such as: 1

❍ ATBLAST (GSA)

❍ CONWEP (U.S. Army Engineer Research and Development 

Center)

Figure 4-6 provides a quick method for predicting the expected 

overpressure (expressed in pounds per square inch or psi) on a 

building for a specific explosive weight and stand-off distance. 

Enter the x-axis with the estimated explosive weight a terrorist 

might use and the y-axis with a known stand-off distance from a 

building. By correlating the resultant effects of overpressure with 

other data, the degree of damage that the various components of 

a building might receive can be estimated. The vehicle icons in 

Figure 4-6 indicate the relative size of the vehicles that might be 

used to transport various quantities of explosives.

The analysis of structures subjected to the effects of an explosion is very complex and requires an understanding of structural 

engineering, dynamics, strengths of materials, and specialized 

training in explosive effects. Such analysis should be performed by 

engineers who can conduct a complex analysis that is both timedependent and accounts for non-linear behavior. In the absence 

of such an analysis of a specific structure, it is possible to provide 

rough approximations of building damages to be expected in an explosive event. Table 4-3 provides basic estimates of incident pressures 

at which different types of damage generally occur to buildings based 

on the incident pressures determined in Figure 4-6. 

 1For security reasons, the distribution of these computer programs is limited. 
EXPLOSIVE BLAST 4-13

Figure 4-6 Incident overpressure measured in pounds per square inch, as a function of stand-off 

distance and net explosive weight (pounds-TNT)

SOURCE: U.S. AIR FORCE, INSTALLATION FORCE PROTECTION GUIDE

Table 4-3: Damage Approximations

Damage Incident Overpressure (psi)

Typical window glass breakage 0.15 – 0.22

Minor damage to some buildings 0.5 – 1.1

Panels of sheet metal buckled 1.1 – 1.8

Failure of concrete block walls 1.8 – 2.9

Collapse of wood framed buildings Over 5.0

Serious damage to steel framed buildings 4 – 7

Severe damage to reinforced concrete structures 6 – 9

Probable total destruction of most buildings 10 – 12

SOURCES: EXPLOSIVE SHOCKS IN AIR, KINNEY & GRAHM, 1985; FACILITY DAMAGE AND PERSONNEL INJURY FROM EXPLOSIVE BLAST,

MONTGOMERY & WARD, 1993; AND THE EFFECTS OF NUCLEAR WEAPONS, 3RD EDITION, GLASSTONE & DOLAN, 1977.

CHEMICAL, BIOLOGICAL, AND RADIOLOGICAL MEASURES 5

CHEMICAL, BIOLOGICAL, AND RADIOLOGICAL MEASURES 5-1

T his chapter is based on guidance from the Centers 

for Disease Control and Protection (CDC)/National 

Institute for Occupational Safety and Health (NIOSH) 

and the DoD and presents protective measures and actions to 

safeguard the occupants of a school building from CBR threats. 

Evacuation, sheltering in place, personal protective equipment, 

air filtration and pressurization, and exhausting and purging 

will be discussed, as well as CBR detection.1 Additionally, CBR 

design mitigation measures are discussed in Chapters 3 and 6, 

and Appendix C contains information on chemical and biological agent characteristics. FEMA 426 Reference Manual to Mitigate 

Potential Terrorist Attacks Against Buildings contains detailed information on CBR threats.

Although the likelihood of a direct attack against a school is very 

low, recent terrorist events have increased interest in the vulnerability of all types of buildings to CBR threats. Of particular 

concern are building HVAC systems, because they can become 

an entry point and distribution system for airborne hazardous 

contaminants. Even without special protective systems, buildings 

can provide protection in varying degrees against airborne hazards that originate outdoors. Conversely, the hazards produced 

by a release inside a building can be much more severe than a 

similar release outdoors. Because buildings allow only a limited 

exchange of air between indoors and outdoors, not only can 

higher concentrations occur when there is a release inside, but 

hazards may persist longer indoors.

Airborne hazardous contaminants can be gases, vapors, or aerosols (small 

solid and liquid particles). Most biological and radiological agents are aerosols, 

whereas most chemical warfare agents are gaseous.

1 This chapter includes a number of protective measures that are included for informational 

purposes only. It is not the intention of FEMA to endorse any particular product or protective 

measure.
5-2 CHEMICAL, BIOLOGICAL, AND RADIOLOGICAL MEASURES 

After the presence of an airborne hazard is detected, there are five 

possible protective actions for a building and its occupants. In increasing order of complexity and cost, these actions are:

1. Evacuation

2. Sheltering in Place

3. Personal Protective Equipment

4. Filtering and Pressurization

5. Exhausting and Purging

These actions are implemented, singly or in combination, when 

a hazard is present or known to be imminent. To ensure these actions will be effective, a school safety emergency plan specific to 

each school, as well as training and familiarization for occupants, 

is required (see Sections 3.11 and 3.12). Exhausting and purging 

is listed last because it is usually the final action after any airborne 

hazard incident.

5.1 EVACUATION

Evacuation is the most common protective action taken when an 

airborne hazard, such as smoke or an unusual odor, is perceived 

in a building. In most cases, existing plans for fire evacuation 

apply. Orderly evacuation is the simplest and most reliable action 

for an internal airborne hazard, but may not be the best action in 

all situations, especially in the case of an external CBR release or 

plume, particularly one that is widespread. If the area covered by 

the plume is too large to rapidly and safely exit, sheltering in place 

should be considered. If a CBR agent has infiltrated the building 

and evacuation is deemed not to be safe, the use of protective 

hoods may be appropriate. Two considerations in non-fire evacuation are: 1) to determine if the source of the airborne hazard 

is internal or external to the building; and 2) to determine if 

evacuation may lead to other risks. Also, evacuation and assembly 

of occupants should be on the upwind side of the building and 

at least 100 feet away, because any airborne hazard escaping the 

structure will be carried downwind.
CHEMICAL, BIOLOGICAL, AND RADIOLOGICAL MEASURES 5-3

5.2 SHELTERING IN PLACE

Typically, buildings offer little protection to occupants from airborne hazards outside the structure because outdoor air must 

be continuously introduced to provide a comfortable, healthy 

indoor environment. However, a school can provide substantial 

protection against agents released outdoors if the flow of fresh 

air is filtered/cleaned, or temporarily interrupted or reduced. 

Interrupting the flow of fresh air is the principle applied in the 

protective action known as sheltering in place. Additional information can be found in Section 3.4 and Chapter 6 of this primer.

The need for schools to consider sheltering in place is demonstrated in Figure 5-1, which depicts the results of modeling a 

chemical dispersion from a rail line assuming local prevailing 

winds. Note that the chemical plume travels directly over a nominal elementary school.

 Figure 5-1 Example of chemical dispersion 
5-4 CHEMICAL, BIOLOGICAL, AND RADIOLOGICAL MEASURES 

The advantage of sheltering in place is that it can be implemented 

rapidly. The disadvantage is that its protection is variable and diminishes with the duration of the hazard. Sheltering requires that 

two distinct actions be taken without delay to maximize the passive 

protection a school building provides: 

❍ First, reduce the indoor-outdoor air exchange rate before 

the hazardous plume arrives. This is achieved by closing all 

windows and doors, and turning off all fans, air conditioners, 

and combustion heaters. 

❍ Second, increase the indoor-outdoor air exchange rate as 

soon as the hazardous plume has passed. This is achieved by 

opening all windows and doors, and turning on all fans to 

ventilate the building. 

The level of protection that can be attained by sheltering in place 

is substantial, but it is less than can be provided by high-efficiency filtration of the fresh air introduced into the building. The 

amount of protection varies with:

❍ The building’s air exchange rate. The tighter the school 

building (i.e., the lower the air exchange rate), the greater 

the protection it provides. In most cases, air conditioners and 

combustion heaters cannot be operated while sheltering in 

place because operating them increases the indoor-outdoor 

exchange of air. 

❍ The duration of exposure. Protection varies with time, 

diminishing as the time of exposure increases. Sheltering 

in place is, therefore, suitable only for exposures of short 

duration, roughly 2 hours or less, depending on conditions. 

❍ Purging or period of occupancy. How long students, faculty, 

and staff remain in the building after the hazardous plume 

has passed also affects the level of protection. Because the 

school building slowly purges contaminants that have entered 

it, at some point during plume passage, the concentration 
CHEMICAL, BIOLOGICAL, AND RADIOLOGICAL MEASURES 5-5

inside exceeds the concentration outside. Maximum 

protection is attained by increasing the air exchange rate after 

plume passage or by exiting into clean air. 

❍ Natural filtering. Some filtering occurs when the agent is 

deposited in the school shell or upon interior surfaces as air 

passes into and out of the building. The tighter the school 

building, the greater the effect of this natural filtering. 

In a home, taking the actions required for sheltering (i.e., closing 

windows and doors, and turning off all air conditioners, fans, and 

combustion heaters) is relatively simple. Doing so in a school may 

require more time and planning. All air handling units must be 

turned off and any dampers for outside air must be closed. Procedures for a protective action plan, therefore, should include:

❍ Identifying all air handling units, fans, and the switches 

needed to deactivate them.

❍ Identifying cracks, seams, joints, and pores in the building 

shell to be temporarily sealed to further reduce outside air 

infiltration. Keeping emergency supplies, such as duct tape 

and polyethylene sheeting, on hand. 

❍ Identifying procedures for purging after an internal release 

(i.e., opening windows and doors, turning on smoke fans, air 

handlers, and fans that were turned off) to exhaust and purge 

the building.

❍ Identifying school safe rooms (i.e., interior rooms having a 

lower air exchange rate – see Chapter 6) that may provide a 

higher level of passive protection. It may be desirable to go to 

a predetermined sheltering room (or rooms) and:

• Shut and lock all windows and doors

• Seal any windows and vents with plastic sheeting and duct 

tape
5-6 CHEMICAL, BIOLOGICAL, AND RADIOLOGICAL MEASURES 

• Seal the door(s) with duct tape around the top, bottom, and 

sides

• Firmly pack dampened towels along the bottom of each door

• Turn on a TV or radio that can be heard within the shelter 

and listen for further instructions

• When the “all clear” is announced, open windows and doors

Although sheltering is for protection against an external release, 

it is possible, but more complex, to shelter in place on one or 

more floors of a multi-story school building after an internal 

release has occurred on a single floor. Important considerations 

for use of sheltering in place are that stairwells must be isolated 

by closed fire doors, elevators must not be used, and clear evacuation routes must remain open if evacuation is required. Escape 

hoods may be needed if the only evacuation routes are through 

contaminated areas. 

One final consideration for sheltering in place is that students, 

faculty, and staff cannot be forced to participate. During an event, 

some building emergency plans call for making a concise information announcement, and then giving occupants 3 to 5 minutes to 

proceed to the sheltering area or evacuate the building before it is 

sealed. It is important to develop a plan in cooperation with likely 

participants and awareness training programs that include discussions of sheltering in place and events (CBR attacks, hazardous 

material releases, or natural disasters) that might make sheltering 

preferable to evacuation. Training programs and information announcements during an event should be tailored to help students, 

faculty, and staff to make informed decisions.

5.3 PERSONAL PROTECTIVE EQUIPMENT

A wide range of individual protection equipment is available, 

including respirators, protective hoods, protective suits, CBR detectors, and decontamination equipment. 
CHEMICAL, BIOLOGICAL, AND RADIOLOGICAL MEASURES 5-7

Of particular note, new models of universal-fit escape hoods have 

been developed for short-duration “escape-only” wear to protect 

against chemical agents, aerosols (including biological agents), 

and some toxic industrial chemicals. These hoods are compact 

enough to be stored in desks or to be carried on the belt. They should be stored 

in their sealed pouches and opened 

only when needed. Most of these hoods 

form protective seals at the neck and do 

not require special fitting techniques 

or multiple sizes to fit a large portion of 

the population. Training is required to 

use the hoods properly. Depending on 

hood design, the wearer must bite on and 

breathe through a mouth bit or use straps 

to tighten a nose cup around the nose 

and mouth (see Figure 5-2). Escape hoods 

should be considered, but may not be an 

effective or efficient proposed solution for 

use in schools, under current threats. 

There are no government standards for 

hoods intended for protection against the 

malicious use of chemical or biological 

agents. In selecting an escape hood, a 

purchaser should, therefore, require information on laboratory verification testing. 

Plans should be made for training, fitting, 

storing, and maintaining records relative to storage life, and there 

should be procedures for instructing building occupants about 

when to put on the hoods. Wearing a hood can cause physiological 

strain and may cause panic or stress that could lead to respiratory 

problems in some people. Finally, it should be recognized that 

no single selection of personal protective equipment is effective 

against every possible threat. Selection must be tied to specific 

threat/hazard characteristics.

 SOURCE: MSA INTERNATIONAL

Figure 5-2 Universal-fit escape hood
5-8 CHEMICAL, BIOLOGICAL, AND RADIOLOGICAL MEASURES 

5.4 AIR FILTRATION AND PRESSURIZATION

Among the various protective measures for school buildings, 

high-efficiency air filtration/cleaning provides the highest level 

of protection against an outdoor release of hazardous materials. It can also provide continuous protection, unlike other 

approaches for which protective measures are initiated upon 

detecting an airborne hazard. Chapter 6 and FEMA 426 Reference 

Manual to Mitigate Potential Terrorist Attacks Against Buildings discuss air filtration in detail.

Two basic methods of applying air filtration to buildings are 

external filtration and internal filtration. External filtration involves drawing air from outside, filtering and/or cleaning it, and 

discharging the air inside the building or protected zone. This 

provides a higher level of protection, but involves substantially 

higher costs. Internal filtration involves drawing air from inside 

the building, filtering and/or cleaning it, and discharging the air 

back inside the building. 

The relative levels of protection of the two methods can be illustrated in terms of protection factor, and the ratio of external dose 

and internal dose (concentration integrated over time). External 

filtration systems with high-efficiency filters can yield protection 

factors greater than 100,000. For internal filtration, the protection 

factors are likely to be less and are highly variable. The protection 

of internal filtration varies with a number of factors, including 

those listed in Section 5.2, the efficiency of the filter, flow rate of 

the filter unit, and size of the room or building in which the filter 

unit operates.

5.5 EXHAUSTING AND PURGING

Turning on building ventilation fans and smoke-purge fans is a 

protective action for purging airborne hazards from the building 

and reducing the hazard to which school occupants are exposed, 

but it is mainly useful when the source of the hazard is indoors. 
CHEMICAL, BIOLOGICAL, AND RADIOLOGICAL MEASURES 5-9

Purging must be carefully applied with regard to the location of 

the source and the time of the release. It must be clear that the 

source of the hazard is inside the school building and, if not, 

purging should not be attempted. If the hazardous material has 

been identified before release or immediately upon release, 

purging should not be employed, because it may spread the hazardous material throughout the school building or HVAC zone. In 

this case, all air handling units should be turned off to isolate the 

hazard while evacuating or temporarily sheltering in place. 

Additionally, the ventilation system and smoke purge fans can be 

used to purge the building following an external release after the 

hazard outdoors has dissipated, and it has been confirmed that 

the agent is no longer present near the school building. 

5.6 CBR DETECTION

Most strategies for protecting students, faculty, staff, and visitors 

from airborne hazards will require a means of detection (i.e., 

determining that a hazard exists). Although effective and inexpensive devices are widely available to detect, for example, smoke and 

carbon monoxide, there are no detectors that can rapidly alert occupants to a broad range of chemical and biological hazards.

Chemical detection technology has improved vastly since Operation Desert Storm, where many military detection systems 

experienced high false alarm rates, but biological detection 

technology has not matured as fast. Biological signatures are not 

as distinctive as chemical signatures and can take 30 minutes or 

more to detect. Biological detection systems are expensive and 

generally require trained specialists to operate. Current chemical 

detectors work in approximately 10 seconds; furthermore, wide varieties of efficient radiological detectors have been developed for 

the nuclear industry and are commercially available.

Chemical Detectors. Driven largely by a desire to protect workers 

from toxic vapors in industrial environments, considerable information is known on the toxicity of chemical warfare agents, 

which often have dual uses in industry. A variety of detection tech-
5-10 CHEMICAL, BIOLOGICAL, AND RADIOLOGICAL MEASURES 

nologies exist, ranging from inexpensive manual point detection 

devices (e.g., paper strips and calorimetric tubes) utilizing basic 

chemical reactions to trigger color changes, to sophisticated detection systems utilizing advanced technologies.

Chemical agents do not possess universal properties that permit detection by any single method. Therefore, most chemical detectors are 

designed to detect specific agents or a group of related agents. Most 

broad range detection systems actually combine several different 

sensors utilizing different technologies and can be very expensive 

and complex. Nevertheless, today there are numerous commercially 

available chemical detectors. The most capable detectors utilize ion 

mobility spectrometry (IMS), surface acoustic wave (SAW), or gas 

chromatograph/mass spectrometer (GC/MS) technologies to detect 

chemical agents and toxic industrial materials (TIMs).

Today, there are commercially available IMS 

detection systems that will detect most chemical 

agents and many TIMs (see Figure 5-3). They 

are suitable for integration into a building 

ventilation system, can interface with HVAC 

control systems, have reasonable maintenance 

requirements (every 3 months), low false alarm 

rates, and can be programmed to detect specific chemical agents. 

Biological Detectors. The current state of 

biological detection technology is very different from that of chemical agent detection 

technology. In general, most biological detection systems are 

currently in the research and early development stages. There 

are some commercially available devices that have limited utility 

(responding only to a small number of agents) and are generally 

high cost items. Because commercially available biological warfare 

(BW) detection systems and/or components exhibit limited utility 

in detecting and identifying BW agents and are also costly, it is 

strongly recommended that purchasers be very careful when considering any device that claims to detect BW agents.

Figure 5-3 

An IMS chemical detector designed for 

installation in HVAC systems 

SOURCE: SMITHS DETECTION
CHEMICAL, BIOLOGICAL, AND RADIOLOGICAL MEASURES 5-11

5.7 INDICATIONS OF CBR CONTAMINATION

Most hazardous chemicals have warning properties that provide 

a practical means for detecting a hazard and initiating protective 

actions. Such warning properties make chemicals perceptible; for 

example, vapors or gases can be perceived by the human senses 

(i.e., smell, sight, taste, or irritation of the eyes, skin, or respiratory tract) before serious effects occur. The distinction between 

perceptible and imperceptible agents is not an exact one. The 

concentrations at which a person can detect an odor vary from 

person to person, and these thresholds also vary relative to the 

concentration that can produce immediate, injurious effects.

Most of the industrial chemicals and chemical-warfare agents are 

readily detectable by smell. Soldiers in World Wars I and II were 

taught to identify, by smell, such agents as mustard, phosgene, and 

chlorine, and this detection method proved effective for determining when to put on and take off a gas mask. An exception is 

the chemical-warfare agent Sarin, which is odorless and colorless 

in its pure form and, therefore, imperceptible. Among the most 

common toxic industrial chemicals, carbon monoxide is one of 

the few that is imperceptible. Because it is odorless and colorless, 

it causes many deaths in buildings each year (see Section 6.2.1).

Biological agents are also imperceptible and there are no detection devices that can determine their presence in the air in real 

time. Current methods for detecting bacterial spores, such as 

anthrax, require a trained operator and expensive equipment. It 

is not currently possible to base protective responses to biological 

agents on detection.

Researchers are working on a prototype device to automatically and 

continuously monitor the air for the presence of bacterial spores. 

The device would continuously sample the air and use microwaves 

to trigger a chemical reaction, the intensity of which would correspond to the concentration of bacterial spores in the sample. If an 

increase in spore concentration is detected, an alarm similar to a 

smoke detector would sound and a technician would respond and 
5-12 CHEMICAL, BIOLOGICAL, AND RADIOLOGICAL MEASURES 

use traditional sampling and analysis to confirm the presence of anthrax spores. Researchers hope the device response time will be fast 

enough to help prevent widespread contamination.

In the absence of a warning property, people can be alerted to 

some airborne hazards by observing symptoms or effects in others. 

This provides a practical means for initiating emergency plans, because the susceptibility to hazardous materials varies from person 

to person. The concentrations of airborne materials may also vary 

substantially within a given building or room, producing a hazard 

that may be greater to some occupants than to others.

Other warning signs of a hazard may involve seeing and hearing 

something out of the ordinary, such as the hiss of a rapid release 

from a pressurized cylinder. Awareness of warning properties, 

signs, and symptoms in other people is the basis of an emergency 

plan (see Sections 3.11 and 3.12). Such a plan should apply four 

possible protective actions: evacuating, sheltering in place, using 

protective masks, and exhausting and purging, as already discussed in this chapter.

For protection against imperceptible agents, the only practical 

protective measures are those that are continuously in place, such 

as filtering all air brought into the building on a continuous basis 

and using automatic, real-time sensors that are capable of detecting the imperceptible agents.

CBR materials, as well as industrial agents, may travel in the 

air as a gas or on surfaces we physically contact. Dispersion 

methods may be as simple as placing a container in a heavily 

used area, opening a container, or using conventional (garden)/

commercial spray devices, or as elaborate as detonating an 

aerosol. Most chemical warfare agents are gaseous, and biological and radiological agents are largely aerosols. 

Chemical incidents are characterized by the rapid onset (minutes 

to hours) of medical symptoms and easily observed indicators 
CHEMICAL, BIOLOGICAL, AND RADIOLOGICAL MEASURES 5-13

(e.g., colored residue, dead foliage, pungent odor, and dead animals, birds, fish, or insects; see Table 5-1 and Figure 5-4). 

In the case of a biological incident, the onset of symptoms takes 

days to weeks and, typically, there will be no characteristic indicators (see Table 5-2 and Figure 5-5). Because of the delayed onset 

of symptoms in a biological incident, the area affected may be 

greater due to the migration of infected individuals.

In the case of a radiological incident, the onset of symptoms also 

takes days to weeks to occur and typically there will be no characteristic indicators (see Table 5-3 and Figure 5-6). Radiological 

materials are not recognizable by the senses because they are colorless and odorless. 

Specialized equipment is required to determine the size of the affected area and if the level of radioactivity presents an immediate 

or long-term health hazard. Because of the delayed onset of symptoms in a radiological incident, the affected area may be greater 

due to the migration of contaminated individuals.

Table 5-1: Indicators of a Possible Chemical Incident

Dead animals, birds, fish Not just an occasional roadkill, but numerous animals (wild and domestic, small and large), 

birds, and fish in the same area. 

Lack of insect life If normal insect activity (ground, air, and/or water) is missing, check the ground/water surface/

shore line for dead insects. If near water, check for dead fish/aquatic birds. 

Physical symptoms Numerous individuals experiencing unexplained water-like blisters, wheals (like bee stings), 

pinpointed pupils, choking, respiratory ailments and/or rashes. 

Mass casualties Numerous individuals exhibiting unexplained serious health problems ranging from nausea to 

disorientation to difficulty in breathing to convulsions to death. 

Definite pattern of casualties Casualties distributed in a pattern that may be associated with possible agent dissemination 

methods. 

Illness associated with confined 

geographic area Lower attack rates for people working indoors than those working outdoors, and vice versa. 
5-14 CHEMICAL, BIOLOGICAL, AND RADIOLOGICAL MEASURES 

Unusual liquid droplets Numerous surfaces exhibit oily droplets/film; numerous water surfaces have an oily film. (No 

recent rain.) 

Areas that look different in 

appearance

Not just a patch of dead weeds, but trees, shrubs, bushes, food crops, and/or lawns that are 

dead, discolored, or withered. (No current drought.) 

Unexplained odors

Smells may range from fruity to flowery to sharp/pungent to garlic/horseradish-like to bitter 

almonds/peach kernels to new mown hay. It is important to note that the particular odor is 

completely out of character with its surroundings. 

Low-lying clouds Low-lying cloud/fog-like condition that is not explained by its surroundings. 

Unusual metal debris Unexplained bomb/munitions-like material, especially if it contains a liquid. (No recent rain.) 

Figure 5-4 Placards associated with chemical incidents

Gases – Toxic and/or Corrosive

Substances – Toxic 

(Non-Combustible)

Gases – Toxic (Corrosive)

Table 5-1: Indicators of a Possible Chemical Incident (continued)
CHEMICAL, BIOLOGICAL, AND RADIOLOGICAL MEASURES 5-15

Infectious Substances

Table 5-2: Indicators of a Possible Biological Incident

Unusual numbers of sick or 

dying people or animals 

Any number of symptoms may occur. As a first responder, strong consideration should be 

given to calling local hospitals to see if additional causalities with similar symptoms have been 

observed. Casualties may occur hours to days or weeks after an incident has occurred. The 

time required before symptoms are observed is dependent on the biological agent used and 

the dose received. Additional symptoms likely to occur include unexplained gastrointestinal 

illnesses and upper respiratory problems similar to flu/colds. 

Unscheduled and unusual spray 

being disseminated Especially if outdoors during periods of darkness. 

Abandoned spray devices Devices will have no distinct odors. 

Figure 5-5 Placards associated with biological incidents

Table 5-3 Indicators of a Possible Radiological Incident

Unusual numbers of sick or 

dying people or animals 

As a first responder, strong consideration should be given to calling local hospitals to see if 

additional casualties with similar symptoms have been observed. Casualties may occur hours to 

days or weeks after an incident has occurred. The time required before symptoms are observed 

is dependent on the radioactive material used and the dose received. Additional symptoms 

likely to occur include skin reddening and, in severe cases, vomiting. 

Unusual metal debris Unexplained bomb/munitions-like material. 

Radiation symbols Containers may display a radiation symbol. 

Heat emitting material Material that seems to emit heat without any sign of an external heating source. 

Glowing material/particles If the material is strongly radioactive, it may emit a radioluminescence. 
5-16 CHEMICAL, BIOLOGICAL, AND RADIOLOGICAL MEASURES

Figure 5-6 Placards associated with radiological incidents

Radioactive Materials
SAFE ROOMS WITHIN SCHOOLS 6

SAFE ROOMS WITHIN SCHOOLS 6-1

T his chapter is a work in progress and will be superceded 

by a future FEMA publication (FEMA 442) that will have 

expanded guidance on the subject of safe rooms. It is intended as a standalone description of the concept of safe rooms 

within schools that will resist CBR and blast threats and to provide school board members and decision-makers with the basic 

components of a protective system. 

It is important to note that the probability of either a CBR or 

terrorist explosive event occurring in the United States is small. 

This is evidenced by the relatively few domestic buildings that 

have been targeted by intentional CBR or explosive events compared to the vast number of buildings that might be considered 

vulnerable. To date, two incidents of biological terrorism have 

been recorded and acknowledged to have had significant impacts on coincident populations in the United States: the 2001 

anthrax mailings and the 1984 contamination of restaurants with 

Salmonella bacteria. If a localized CBR event were to occur, the 

potential for contamination to spread and cause collateral illnesses and fatalities up to 4 or more kilometers (approximately 

21⁄2 miles) from the target site would be likely. Unpredictable 

meteorological conditions would play a key role in the spread of 

such CBR contamination. Similarly, if an explosive event were to 

occur, there would be a significant potential for injuries resulting 

from debris impact and structural collapse. Therefore, in consideration of the proximity of some schools with respect to higher 

profile potential targets in the United States, school board members and administrators may determine that their select facilities 

require the design and construction of safe rooms. Because there 

are so many different types of school buildings, with so many different types of construction and materials, it is not possible to 

relate all the following issues to specific building types; nevertheless, an attempt was made to relate the relevant threats and the 

general principles of protective design to the development of safe 

rooms within schools. 
6-2 SAFE ROOMS WITHIN SCHOOLS 

This chapter discusses: 

❍	 The different types of hazards 

❍	 The general means by which these hazards might be addressed

❍	 The protective methods that may be effective

❍	 The level of effectiveness that may be achieved

❍	 The information from which decision-makers can estimate the 

cost for providing different levels of protection

6.1 TYPES OF CBR HAZARDS 

Chemical contaminants of concern are the chemical warfare 

agents (CWAs) and toxic industrial chemicals (TICs). Key 

attributes of CWAs and TICs are their toxicity, volatility, and availability. The most toxic CWAs are the nerve agent liquids, which 

include VX with high toxicity and low volatility, and Sarin with 

high toxicity and moderate volatility. The measured volatility of 

a chemical represents the ease with which the quantity of liquid 

chemical leaves the liquid state and becomes a gas in equilibrium 

with its volumetric surroundings. So, an occupant of a room 

where Sarin liquid is naturally evaporating is at much greater 

risk than the same individual being in the 

same room with the same or (to a degree 

greater) quantity of a naturally evaporating 

VX agent (see Appendix C). The lethality 

of VX exceeds the lethality of Sarin by dose, 

but Sarin is much more volatile than VX. 

6.1.1 Toxic Industrial 

Chemicals

Though of lower toxicity than nerve agents, 

TICs are widely available, and some can be 

easily obtained or produced without sophisticated equipment. Among the hundreds 

of TICs produced worldwide are several 

that have been used as CWAs (e.g., arsine, 

A ranking of 49 TICs with regard to their threat when used 

against buildings applies three factors (availability, toxicity, and 

delivery system) on a scale of 1 to 5, with the highest number 

indicating the greatest hazard. About half of the TICs considered 

“threat agents” are gases at standard conditions and must 

be transported in pressurized cylinders. The military coppersilver-zinc-molybdenum-triethylenediamine (ASZM-TEDA) 

carbon is effective in filtering 22 of these 49 TICs, has marginal 

performance against 9 TICs, and poor performance against 18 

TICs. The military ASZM-TEDA carbon is a special sub-grade 

of bound with pitch-low (BPL) activated carbon, impregnated 

with salts of copper, silver, zinc, and molybdenum, and with 

triethylenediamine (TEDA) to enhance the carbons adsorption 

characteristics.
SAFE ROOMS WITHIN SCHOOLS 6-3

chlorine, hydrogen cyanide, phosgene, hydrogen sulfide, acrolein, 

and cyanogen chloride). Those that have been used in warfare 

are considered second-rate CWAs because their toxicity and vapor 

pressure make them less effective than other agents for open-air 

battlefield use. 

6.1.2 Incapacitating and Tear-producing 

Agents

Although incapacitating and tear-producing agents are considered 

non-lethal, indoor releases can, under certain conditions, produce 

lethal concentrations. In addition to the tear-producing agents, there 

are commercially available agents containing oleoresin capsicum 

(OC), the natural oil of chili peppers. The malicious or accidental release of pepper spray has caused many disruptive incidents in recent 

years. In contact with the eyes, nose, or mouth, OC causes immediate 

pain and inflammation. Inhaled, its aerosol 

causes choking and gasping for breath. Of low 

vapor pressure, OC is easily filtered.

6.1.3 Biological Agents

Biological agents include bacteria, viruses, 

and rickettsia. Toxins, which are poisons of 

biological origin and not living organisms, are 

sometimes grouped with biological agents and 

sometimes with chemical agents. Although 

there are hundreds of microorganisms that 

could be used as biological agents, the likely 

number is much smaller when the agents’ 

effectiveness, reliability, availability, ease of 

manufacture, and stability in storage and 

dissemination are considered. When disseminated as aerosols, biological agents are most 

effective in the size range of 1 to 5 microns, 

because they can remain suspended for long 

periods. Smaller particles are less likely to 

survive as aerosols, and larger particles settle 

rapidly, making them less likely to enter the 

HEPA filters were developed during World War II by the Atomic 

Energy Commission to remove radioactive dust particles from 

research spaces. Today, HEPA filters are used for various 

applications, including nuclear contamination, asbestos 

abatement, surgical facilities, tuberculosis wards, clean rooms, 

computer rooms, and other critical areas. A HEPA filter is 99.97 

percent efficient in capturing particles 0.3 micron in diameter. 

HEPA filters are top of the line particulate filters. Although they 

are very good at filtering particles, they are also expensive to 

operate because they cause large drops in pressure. Therefore, 

they are generally only used in “high end” applications such as 

those mentioned above. HEPA filters are standard components 

with high-efficiency gas adsorber (HEGA) systems. These military 

adsorbers cost approximately $4.50 per cubic feet per minute 

(cfm), and their expected service life is 3 years, although service 

life varies with the air quality of the region and the moisture to 

which the filters are exposed over time. Use of only HEPA filters 

in a makeup-air unit would provide a high level of protection 

from biological agents, radiological agents, solid aerosols such as 

tear gas, and liquid aerosols of low vapor pressure.
6-4 SAFE ROOMS WITHIN SCHOOLS 

lungs. The settling time in still air for an anthrax spore (1 micron 

by 0.7 micron in size) is approximately 1⁄2 foot per hour. Particles 

of this size are readily filtered from an air stream with high-efficiency particulate air (HEPA) filters. Toxins, which may be in 

crystalline or liquid form, are also filterable with HEPA when disseminated as aerosols.

6.1.4 Radiological Agents

Radiological agents are radioactive materials. Explosive release is 

the most likely means of disseminating such agents in a terrorist 

attack (e.g., a “dirty bomb” consisting of radioactive material 

packaged with a conventional explosive). The likely radioactive 

ingredients are those used for industrial and medical purposes 

(e.g., isotopes of cesium, cobalt, and iridium). They are commonly 

found in hospitals and labs, often with few safeguards. Given the 

availability of nuclear reactors for research or energy production by universities, research facilities, or private industries, the 

threat associated with radiological materials is significant. Radiological contaminants are very persistent, in that their decay rate 

is extremely slow. Unlike chemical or biological agents, decontamination involves only removal, not neutralization. Radiological 

aerosols present a health hazard if ingested or inhaled, but are 

easily filtered from an air stream with HEPA filters.

6.2 MOST LIKELY DELIVERY METHODS FOR 

CBR AGENTS

For purpose of vulnerability assessments, delivery methods are 

divided into four types of releases: internal, external proximate, 

remote, and remote with forewarning.

6.2.1 Internal Release

This involves transporting a container of agent into a building 

and releasing the contents manually, automatically, or remotely. 

Such a device may rely simply upon natural evaporation (as in 

the Tokyo subway Sarin attack), with the rate of evaporation 

proportional to the surface area that develops as liquid agent 
SAFE ROOMS WITHIN SCHOOLS 6-5

spills from its container. Aerosolization may occur with movement of an open package or letter containing a biological agent. 

A sprayer powered by batteries or compressed air can produce 

an effective dose of an agent quite rapidly. An agent can be 

released in any area served by return ducts/plenums or in a 

mechanical room, with dissemination through an air-handling 

unit. Biological agents can also be placed into certain types of 

humidifier systems. 

6.2.2 External Proximate Release

This involves introducing an agent or a dissemination device 

from outside the building directly through a penetration in 

the building shell, such as a fresh-air intake. Vulnerability to 

this type of release is highest when air intakes are at accessible, 

unsecured locations at ground level. Agents can also be delivered through other penetrations, but potential effectiveness is 

less in the absence of a driving force (a fan) to introduce and 

distribute air within the building. A documented example of 

an attack through a ground-level penetration is the release of a 

toxic industrial gas from a pressurized cylinder through a dryer 

vent. External proximate release also includes forcing open or 

breaking windows and doors to introduce agents from pressurized cylinders or tossing a grenade or container of an agent into 

the building. 

6.2.3 Remote Release

If directed at a specific facility, this type of attack involves a plume, 

puff, or line source generated so that the wind carries the agent 

to the target building; the facility may be the target or collaterally 

in the direction of the attack. The most efficient type of remote 

attack is a directed-plume attack with a ground-level source placed 

upwind of a building’s fresh-air intakes or open windows. A 

ground-level, directed-plume attack was conducted with the nerve 

agent Sarin from a distance of 60 yards in Matsumoto, Japan, in 

1994, killing 7 and injuring 264 in a zone 500 yards deep and 

100 yards wide. A remote attack can also involve an aerial release. 

Release from an aircraft is much less likely to affect a specific, 
6-6 SAFE ROOMS WITHIN SCHOOLS 

targeted building, however, because the vertical rate of transport, 

governed by settling time and atmospheric stability, is extremely 

difficult to judge. 

6.2.4 Remote Release with Forewarning

This type of attack differs from other remote releases because 

protective actions other than those for no-warning attacks can be 

applied. This type involves warning in the form of an explosion or 

an event such as an accidental or intentional release of an agent 

from a chemical transport or storage tank. Scenarios involving 

forewarning include sabotage of toxic industrial storage tanks/

trucks, transport accidents, fires, or the impending release of a 

chemical agent from a point upwind of the building. Quantities 

of agent that could be released from a single 3,000-gallon tanker 

truck are approximately 34,000 pounds for phosgene, 35,000 

pounds for chlorine, and 17,000 pounds for hydrogen cyanide.

Scenarios

Aside from the recent attacks with mail-delivered anthrax of the past year, no CBR terrorist attacks have occurred on U.S. Federal 

Government facilities; therefore, based on precedence, the probability of such attacks is very low. Without intelligence information indicating 

that a specific group or person possesses plans, knowledge, resources, and motivation to carry out a CBR attack, the likelihood of such an 

attack can be estimated only by factors unrelated to specific groups. These factors relate to the target, environmental conditions, and difficulty 

of attack. Target factors include the value or symbolism of the target, recognizability, and appearance of vulnerability. Factors that relate to 

the difficulty of attack and conditions are: availability of the agent, complexity of the delivery method/system, effect of weather, standoff 

distance, and deterrence (risk to the attacker, likelihood of being observed/thwarted).

There is no justification on the basis of precedence to identify a school as a probable target for a direct terrorist attack. However, a school may be 

located in the vicinity of other U.S. government buildings or other iconic properties that may be more recognizable and of greater perceived target 

value. The more likely scenario for such schools, therefore, is one of collateral effects resulting from a remote release. General scenarios for remote 

release are presented below, followed by internal/proximate scenarios that would involve directly targeting a building. 

6.3 VULNERABILITY TO REMOTE CBR 

RELEASE

In the absence of a secure perimeter around the building (see 

Section 2.4) and a real-time detection system, vulnerability to a 

remote release is determined by: 1) the efficiency of the school 
SAFE ROOMS WITHIN SCHOOLS 6-7

building’s filtration system in removing aerosols 

and gases, 2) the unfiltered component of air 

exchange, and 3) the configuration of the school 

building and elevation of air intakes. These vulnerabilities can be characterized as follows.

❍	 Efficiency of gas filtration. Generally, if 

adsorbers are found in buildings, they are 

for the purpose of improving indoor air 

quality by removing both outdoor and indoor 

air pollutants, particularly corrosive gases such as sulfur 

dioxide, nitrogen dioxide, and ozone, and are used where 

appropriate for protecting against the deleterious effects of 

these gases. Although not intended for protecting people 

from toxic chemical agents, these gas adsorbers do reduce the 

vulnerability to an attack with certain chemical agents. 

With a 1-inch bed thickness of coarse (4x6 mesh) sorbent 

granules and a short residence time of these indoor air 

quality filters, the efficiency is about 99 percent initially, 

and it diminishes with time in service, typically to about 25 

percent in a year. There is also an initial bypass of roughly 1 

percent through the bed and additional bypasses among filter 

modules’ holding frames. The bypasses may increase with 

time in service, dropping the net efficiency below the initial 

level. This compares with an efficiency of greater than 99.999 

percent for gas adsorbers designed for protection of people in 

military applications. Removal efficiency for these indoor air 

quality adsorbers is relatively low and uncertain for some of 

the threat agents (the capacity for arsine is low, for example). 

Thus, the efficiency and capacity are highly variable. 

Manufacturers provide surveillance testing to determine when 

to change filters and recommend that they be changed when 

reactive capacity has dropped to 25 percent of the initial 

value. The typical service life for single stage, 1-inch beds is 

approximately 1 year.

 Against an external hazard, the level of protection 

provided by a school building with a filtration system 

is defined in terms of protection factor (i.e., the dose 

[concentration integrated over time] of an agent 

outside divided by the resulting dose of agent inside). 

If all makeup air passes through filters, the protection 

factor equals the inverse of the penetration factor of 

the filter (1 minus the filter removal efficiency). 
6-8 SAFE ROOMS WITHIN SCHOOLS 

❍	 Particulate filtration. Significant particulate filtration can 

be accomplished by using a 35-percent pre-filter and a 95-

percent filter in series. The efficiency of this filter train is in 

the range of 95 to 99 percent for 1-micron particles in the new 

condition, and this efficiency increases as the filters load. 

❍	 Unfiltered air exchange. Typical of schools, a substantial 

portion of the air exchanged between indoors and outdoors 

may not pass through the filters of any air-handling units. 

When this occurs, the level of protection the building 

structure provides is, therefore, governed not by the 

efficiency of the filters but rather by that portion of makeup 

air bypassing the filters. There are several paths by which air 

exchange is driven by fans, buoyancy, and/or wind pressures. 

They include operable windows; doorways with flows driven 

by buoyancy, particularly in summer and winter when 

indoor-outdoor temperature differentials are highest; and 

unintentional openings in the building shell. When internal 

resistance is minimal, less dense (buoyant) warm air rises and 

flows out of a school building near its top in winter, drawing 

in cool air at the lower levels. Conversely, in summer, cool 

air falls and flows out of the building’s base. The buoyancy 

effect tends to be less pronounced in spring and fall because 

of smaller indoor and outdoor temperature differences. With 

the standard draw-through configuration of the air-handling 

units, leakage paths at the access doors and panels are subject 

to inward pressure; these leakage paths increase as the gaskets 

age. Typically, access doors also fail to seal well with filter 

frames, allowing bypass that increases with age.

❍	 Typical protection factors achievable. In terms of protection 

factor, protection against aerosols (biological/radiological 

agents and others such as tear gas) provided by the best 

(standard) filtration systems available in air-handling units is 

substantial, but relatively low (in the range of approximately 

5 to 50). Protection factor is a ratio of dose (concentration 

integrated over time) of an agent outside divided by the 

resulting dose of agent inside a building). This level of 
SAFE ROOMS WITHIN SCHOOLS 6-9

protection is comparable to that achievable with sheltering in 

place or an active detection-based system that responds by deenergizing fans and closing dampers. The higher value in this 

range is estimated by taking the inverse of the penetration 

factor for 1-micron particles through the filters, including an 

initial bypass of approximately 1 percent. The lower value in 

the protection-factor range is estimated for both particulate 

and gas filters by using 20 percent as an estimate of the unfiltered 

air exchange; the inverse of the penetration factor (0.2) is 5. 

With an indoor air quality filter unit having a gas adsorber, the 

protection factor for gases can be as high as 50, but only when 

filters are new and only with gas adsorbers. The protection 

drops to a low value as the filter efficiency decreases with time 

in service. This may be less than 2 if the efficiency drops below 

50 percent after 1 year in service. The protection factor against 

gases is also reduced by the portion of outside air (which 

could be at least 80 percent) that does not flow through gas 

adsorbers. With a penetration of 80 percent, the protection 

factor for gases for the whole building is less than 2.

Summary: Vulnerability to Remote Release 

A typical building would have high vulnerability to a remote release of aerosols (biological and radiological agents) and a high 

vulnerability to a remote release of gases (chemical agents). The basis for this rating is:

❍	 Estimated protection factors are in the range of 5 to 50 for aerosols, based on a substantial volume of unfiltered air exchange.

❍	 Use of gas adsorbers is atypical of building air-handling ventilation systems. 

❍	 Outside air intakes in building construction are often located near ground level, making them especially vulnerable. 

Vulnerability can be reduced by:

❍	 Application of gas adsorbers to all air-handling units

❍	 Employing particulate filters of higher efficiency (e.g., 95 percent) and low bypass 
6-10 SAFE ROOMS WITHIN SCHOOLS 

6.4 VULNERABILITY TO REMOTE CBR 

RELEASE WITH FOREWARNING 

This type of attack involves release of agent by explosion or rapid 

release from a tanker truck, rail car, or fixed storage tank. The 

potential for this type of attack is higher when the facility is near 

rail lines, public roads with truck traffic, or storage tanks of toxic 

chemicals. This type of attack may also involve an explosive release 

of a radiological agent (i.e., a “dirty bomb” attack at a distance 

from the building great enough to allow for protective actions to 

be taken before wind carries the agent to the building).

The criterion for this aspect of vulnerability is the ability to rapidly 

assume a sheltering-in-place posture (see Section 5.2). The main 

requirements are plans/procedures for sheltering, controls to 

rapidly turn off all fans, and a communications or public address 

system to facilitate closing of doors and keeping them closed while 

an outdoor hazard is present or imminent. Protection factors vary, 

diminishing with time of exposure; however, scenarios of explosive 

release under most conditions would present a relatively short exposure to the school building.

Summary: Vulnerability to Remote CBR Release With Forewarning

A typical school building would have high vulnerability to a remote release with forewarning. The basis for this rating is:

❍	 Schools should develop plans/procedures for sheltering and rapid deactivation of all fans and closing of doors and windows.

❍	 Schools have limited filtration capabilities for gases and aerosols; therefore, the vulnerability to a remote release with 

forewarning is aproximately the same as the vulnerability to a remote release without forewarning. 

Vulnerability can be reduced by:

❍	 Developing an emergency plan for sheltering in place that includes rapidly de-energizing all fans and closing doors and 

windows. 
SAFE ROOMS WITHIN SCHOOLS 6-11

6.5 VULNERABILITY TO INTERNAL CBR 

RELEASE 

This is a remote possibility owing to the nature and likelihood of 

other vandalism and that actual targeting of a school has no historical precedence. Nevertheless, internal releases involve covert 

entry or covert introduction of agents in containers. Vulnerability 

to internal release is, therefore, determined principally by physical 

security measures in place. Containers of agents may be hand-carried or delivered in mail, supplies, or equipment. Other factors 

affecting this vulnerability are internal (recirculation) filtration 

and how well entry zones where any screening takes place are isolated architecturally and mechanically. 

The basis for preventing covert introduction of agents is access 

control and entry screening. Use of the X-ray machine for handcarried items facilitates the detection of containers large enough 

to hold hazardous quantities of chemical agents; however, it 

requires specific operating procedures for doing so, and it may 

not be effective in detecting containers of hazardous quantities 

of biological agents. Obviously, such procedures are not recommended for schools without provocation (i.e., an actual threat) 

because of cost. 

6.6 VULNERABILITY TO EXTERNAL 

PROXIMATE CBR RELEASE

Vulnerability to external proximate release is determined mainly 

by the accessibility of outside air intakes to covert introduction of 

agent or agent-dissemination device. Unless air intakes are relocated at a higher elevation, this vulnerability would remain high.

The three strategies for protecting a school building from airborne hazards originating outdoors are air filtration, controlling 

air exchange, and exclusion by physical security. Options presented in this chapter focus on air filtration; however, enhanced 

filtration techniques discussed earlier would be applied most 

economically in schools to a selected safe room, such as a school 
6-12 SAFE ROOMS WITHIN SCHOOLS 

gymnasium or auditorium. Without a secure exclusion zone 

around the school building, physical security measures are limited 

to those described above for external proximate release and internal release.

Controlling air exchange is most commonly employed with 

human detection and warning (i.e., sheltering in place). It can 

also be applied with automatic, real-time detection equipment, 

but with very limited effectiveness. Few agents among the full 

spectrum of threat agents can be detected with accuracy in real 

time. Protection factors vary with response time and, even with 

instantaneous response, protection factors are no greater than 

the maximum protection factors achievable with sheltering in 

place. As the response time increases, protection factors diminish. 

With current technology, response times are longest for biological 

agent detection. The response time for presumptive identification 

by a detector such as the Joint Biological Point Detection System 

is approximately 30 minutes and far exceeds the response time 

needed for effective use of sheltering in place. A biological detection system would not, therefore, prevent the contamination of a 

particular building.

❍	 Criteria for protective performance. All of the following 

discussion represents extreme measures applied to high-risk, 

high-security assets or, in general, to lesser degrees, safe rooms, 

and perhaps to would-be safe rooms for schools. There is no 

standard requirement for protection factors. U.S. military systems 

are designed to achieve protection factors greater than 10,000. 

The criterion applied to military masks and collective protection 

shelters is 6,667, which is based upon 

specific levels for chemical agents on the 

battlefield and for threshold effects of 

the chemical agents on soldiers. There is 

no criterion for biological or radiological 

agents based upon concentrations and 

doses likely to be developed in an attack 

on a school building; however, it would 

be 10,000 or greater. 

To increase the protection factors to 10,000 or higher for selected 

envelopes requires: 1) high-efficiency filters (HEPA and HEGA) with 

leak-tight seals at the holding frames; 2) pressurization of the protective 

envelope; 3) pressurization of mechanical rooms in which air-handling 

units are located and return ducts not within the protective envelope; 4) 

adding vestibules/airlocks at entrances to protected zones where entry/

exit is frequent; and 5) permanently closing windows.
SAFE ROOMS WITHIN SCHOOLS 6-13

The selection of a CBR safe room in a school building requires 

an assessment of factors contributing to infiltration (or wind penetration from the outside). To prevent infiltration through the 

protected envelope requires an internal pressure of approximately 

50 Pascals [0.2 inch, water gauge (iwg)]. This pressure does not 

prevent infiltration driven by buoyancy and wind pressures under 

all possible conditions, but it does so under wind conditions most 

conducive to a (stand-off) plume attack (see Table 6-1). The level 

of safe room pressurization should exceed 95-99 percent of the 

meteorological conditions for the given school location. Note 

that wind does not exert a uniform pressure on a building face; 

the pressure varies by location on the building face and the angle 

of incidence. A 20 mile-per-hour (mph) wind velocity is not uncommon in the United States and, thus, a safe room pressurized 

to 50 Pascals would prevent infiltration from time averaged 20 

mph winds. 

Table 6-1: Pressures Exerted on a School Building Face by Wind

Wind Velocity* [mph] From [Pascal] To [Pascal]

2 0.2 0.4

4 1.0 1.7

6 2.2 3.9

8 3.9 6.9

10 6.0 10.8

15 13.5 24.4

20 24.1 43.3

25 37.6 67.7

*Time Averaged and Normal (90%) Incidence to School Building Face

There are several options for improving protection factors with 

filtration; they involve both the type/configuration of the filter 

system and the extent of the protective envelope. 
6-14 SAFE ROOMS WITHIN SCHOOLS 

❍	 Options for type of filter system. Four options for a dedicated 

type of filtration system for a safe room include:

• Improving mixed-air particulate filtration of air-handling 

units. Particulate filters may be upgraded to 95-percent 

filters, providing the potential for substantial improvement 

in protection against biological agent aerosols. The limit 

of protection factor against 1-micron particles, however, 

is approximately 100 with pressurization of the protective 

envelope and reduction of bypass at the filter frames. 

Reduction of bypass requires sealing and gasketing existing 

retainers, slide-in tracks, and access doors, and adding 

gaskets between filter frames in slide-in tracks. Pressurization 

can be achieved by rebalancing the air-handling units and 

controlling the flows through open doorways and windows. 

Among the options for improvement are to upgrade 

the filters to HEPA with leak-tight holding frames; with 

pressurization, this would increase the potential protection 

factor to about 10,000 for biological agents, but not for 

chemical agents. This option requires special holding 

fixtures for the filters and may require replacement of supply 

fans to accommodate higher pressure drop. 

• Improving mixed-air gas filtration of the air-handling 

units. An option to increase protection factors of a school 

building for chemical agents is to install gas adsorbers in 

air-handling units. This would involve adding the indoor air 

quality (IAQ) type adsorbers to existing air-handling units, 

at a cost of $0.50 per cfm. With a 1-year service life, the 

filter replacement costs would be $0.25 per cfm. Additional 

energy related operating costs would be incurred due to the 

pressure drop of the adsorbers (0.75 iwg). This option does 

not provide high efficiency against all chemical agents.

• Installing makeup-air units with HEGA and HEPA filters. 

A makeup air unit for both gases and aerosols includes the 

following components in series: pre-filter, fan, HEPA filter, 

HEGA filter, and heating and cooling coils. The makeup-air 

unit provides filtered outside air to pressurize the protective 
SAFE ROOMS WITHIN SCHOOLS 6-15

envelope. It eliminates recirculation and the internally 

induced infiltration associated with applying a single fan for 

both makeup air and recirculated air. The most cost-effective 

HEGA filter units currently available for protection from 

chemical agents employ the military-standard 200-cfm radialflow filters per MIL-PRF-51527A, “Filter Set, Gas-particulate, 

200 cfm," Type II. These contain ASZM-TEDA carbon of 

12x30 mesh size in 2-inch-deep beds, which removes all 

chemical warfare agents and a substantial number of toxic 

industrial chemicals. These provide removal efficiency 

greater than 99.999 percent throughout their service life 

(estimated at 3 years). HEPA filters are standard components 

with HEGA systems. These military adsorbers cost 

approximately $4.50 per cfm, and their expected service life 

is 3 years, although service life varies with the air quality of 

the region and the moisture to which the filters are exposed 

over time. Maintenance costs run approximately $2 per year 

per cfm. Maintenance also includes changing HEPA filters 

annually and pre-filters every 90 days. With total pressure 

drop of 6 iwg across the adsorber and HEPA filter, energy 

costs for the high-efficiency filtration run approximately 

$0.50 per cfm per year. 

• Installing makeup-air units with HEPA only. Use of only 

HEPA in a makeup-air unit would provide a high level of 

protection from biological agents, radiological agents, solid 

aerosols such as tear gas, and liquid aerosols of low vapor 

pressure. High-level protection against biological aerosols is 

particularly beneficial because there is no capability for realtime detection of biological agents (all strategies that require 

biological detection are mitigation strategies involving 

decontamination and medical treatment). Use of HEPA only 

in a makeup-air unit would substantially reduce hardware 

costs, maintenance costs, and electrical costs of ventilation as 

well as the space requirements for the units. Protection at a 

lower level would still be provided by filtration of recirculated 

air with gas adsorbers in air-handling units. 
6-16 SAFE ROOMS WITHIN SCHOOLS 

6.7 RECOMMENDATIONS FOR CBR 

PROTECTION

The following actions are recommended for CBR protection:

❍	 To provide a substantial level of protection against an external 

release of CBR agents, apply any one of the filtration options 

summarized above to a renovated school gymnasium or 

auditorium safe room. 

❍	 To protect against a remote attack with a chemical or radiological 

agent, plans, procedures, and training for sheltering in place 

should be developed. To support this protective measure, a rapid 

notification system (public address system) and controls for rapid 

deactivation of fans and closing of dampers should be defined. 

A guide for developing protective action plans is available in 

the Army Corps of Engineers draft Technical Instruction TI 

853-01 Protecting Buildings and Their Occupants from Airborne 

Hazards, dated October 2001.

❍	 To reduce vulnerability to internal release, implement security 

procedures specific to entry screening for containers of 

unknown liquids or gases being carried into the secure area. 

Provide training to employees on awareness of the CBR threat 

and the protective action plan.

6.8 SAFE ROOMS IN RESPONSE TO THE 

DOMESTIC EXPLOSIVE THREAT

The concept of safe rooms has been around for quite some time. 

Bomb shelters were used in the United Kingdom (U.K.) during 

World War II to protect the civilian populations against aerial attack and fall-out shelters were established in cities in the United 

States during the Cold War to protect against the lingering effects 

of a feared nuclear attack. More recently, the Israeli Defense Force 

(IDF) requires apartment protected spaces (APSs) or floor protected spaces (FPSs) to be constructed in every new building or to 

be added to existing buildings according to engineering specifications. In buildings in which no shelters exist, interior rooms may 
SAFE ROOMS WITHIN SCHOOLS 6-17

be converted to shelters by following IDF instructions. In all cases, 

the shelters must be accessible within 2 minutes of a warning 

siren. The protected spaces are intended to serve as a refuge when 

an attack is suspected, either through early warning or remote detection; however, the protected space is much less effective when 

the event takes place without warning. Two minutes and eleven 

seconds elapsed between the time the Ryder truck stopped in 

front of the Murrah Federal Building in Oklahoma City and the 

detonation of its explosives, but no one was alerted to the danger 

until the explosion occurred.1 At Khobar Towers in Dhahran, 

Saudi Arabia, U.S. Air Force Security Police observers on the roof 

of the building overlooking the perimeter identified the attack 

in progress and alerted many occupants to the threat; however, 

evacuation was incomplete and 500 people were wounded and 19 

people were killed by the explosion.2

The effectiveness of the safe room in protecting occupants from 

the effects of an explosive detonation is, therefore. highly dependent on early detection and warning. Unless the attacker notifies 

authorities of a bomb threat, as often occurred in the terrorist activities in Northern Ireland, the safe room can best be used after 

an explosion occurs in anticipation of a second attack. The 1998 

bombing of the U.S. Embassy in Kenya was preceded by a small explosion that drew curious embassy employees to the windows; such 

a tactic, if repeated in the United States, would justify the relocation of school occupants to a safe room until school officials are 

able to determined that it is safe to disperse the students. To these 

limited objectives, the establishment of a safe room in schools may 

serve a useful purpose. Given the nature of the explosive threat, 

however, it may be more effective to provide debris mitigating protective measures for all exterior façade elements.

It is important to understand the nature of the domestic explosive 

threat in order to effectively plan for the protection of different 

1 The structural features of the building, including the transfer girders that spanned over the main 

entrances, along with the relatively short distance from the curb to the face of the building, were 

the most significant contributing factors to the collapse.

2 Although the precast structure was subjected to overwhelming blast loads, which blew the front 

façade into the occupied spaces, the building was designed to the U.K. regulations, which have 

provisions for structural robustness that require precast components to be tied together.
6-18 SAFE ROOMS WITHIN SCHOOLS 

types of facilities and particularly for the establishment of safe 

rooms in schools. Although the patterns of past events may not 

predict the future, they give valuable insight to the protection 

against a very low probability, but potentially high consequence 

event. As previously discussed, despite a wide range of terrorist 

events, such as CBR contamination, an explosion remains the 

most insidious threat, requiring the least sophisticated materials 

and expertise. The principal components of an explosive device 

can be obtained at a variety of retail outlets, without arousing 

suspicion. Every year, over 1,000 intentional explosive detonations are reported by the FBI Bomb Data Center. In 1998, the 

last year for which the compiled data were published, there were 

1,225 actual incidents of unauthorized explosions in the United 

States.3 The majority of these explosives were targeted against 

residential properties and vehicles; however, 76 explosive events 

were detonated at educational facilities, causing a total of $28,500 

in property damage.4 In addition to these actual events, 63 incidents involving hoax devices were investigated. By contrast, only 

one explosive device was detonated at a Federal Government 

facility, causing $1.5 million in property damage, and eight were 

detonated at local/state government 

facilities, causing $316,000 in property damage. Over 70 percent of the 

people involved in bombing incidents 

were “young offenders” and less than 

1⁄2 percent were members of terrorist 

groups. Vandalism was the motivation 

in 40 percent of the intentional and 

accidental bombing incidents. Although two out of three attacks were 

perpetrated between 6 p.m. and 6 

a.m., the incidents against educational 

facilities were more uniformly distributed throughout the day. Although 

each successive major domestic terrorist event exceeded the intensity of 

3 U.S. Department of Justice, Federal Bureau of Investigation, General Information Bulletin 98-1.

4 The Bomb Data Center information does not indicate whether any of these events were preceded 

by a warning nor does it indicate the average weight of explosives used.

Types of Explosive Threats

As explained in Chapter 4, the effects of an explosion primarily depend 

on the weight of the explosives, the type of the explosives, and the 

distance from the point of detonation to the protected structure. 

Different types of explosive materials are classified as high energy 

and low energy, and these different classifications greatly influence 

the damage potential of the detonation. High energy explosives, which 

efficiently convert the material’s chemical energy into blast pressure, 

represent less than 1 percent of all explosive detonations reported by 

the FBI Bomb Data Center. The vast majority of the incidents involve low 

energy devices in which a significant portion of the explosive material 

is consumed by deflagration. In these cases, a large portion of the 

material’s chemical energy is dissipated as thermal energy, which may 

cause fires or thermal radiation damage. 
SAFE ROOMS WITHIN SCHOOLS 6-19

the predecessor, this is not particularly relevant to the threats to 

which a school structure might be subjected; if an explosive were 

to be detonated in or around a school building, it would most 

likely be a small improvised device assembled by a youth and vandalism is most likely to be the motive. 

The size of the explosive that might be considered for a protective 

design is limited by the maximum weight that might be transported either by hand or by vehicle (for additional information, 

see Section 4.2). Despite the large weight of explosives that might 

be transported by vehicle, there have been relatively few large-scale 

explosive events within the United States. The 1995 explosion that 

collapsed portions of the Murrah Federal Building in Oklahoma 

City contained 4,800 pounds of ammonium nitrate and fuel oil 

(ANFO) and the 1993 explosion within the parking garage beneath the World Trade Center complex contained 1,200 pounds 

of urea nitrate. As implied by the FBI statistics, the majority of the 

domestic events contain significantly smaller weights of low energy 

explosives. The explosive that was used in the 1996 pipe bomb attack at the Olympics in Atlanta consisted of smokeless powder and 

was preceded by a warning that was called in 23 minutes before 

the detonation. Nevertheless, the protective design of structures 

focuses on the effects of high energy explosives and relates the different mixtures to an equivalent weight of trinitrotoluene (TNT). 

As discussed in Chapter 4, the distance of the protected structure 

from the point of explosive detonation is commonly referred to as 

the stand-off distance. As the front of the shock-wave propagates 

away from the source of the detonation at supersonic speed, it 

expands into increasingly larger volumes of air, the peak incident 

pressure at the shock front decreases, and the duration of the 

pressure pulse increases. The shock front first impinges on the 

leading surfaces of a structure located within its path and then 

engulfs the entire structure. Both the intensity of peak pressure 

and the impulse, which considers the effect of both pressure intensity and pulse duration, affect the hazard potential of the blast 

loading. Other issues, such as the geometry of the waves impacting 

the protected structure and the reflectivity of the surroundings, 

will either amplify or reduce the intensity of the blast loading. 
6-20 SAFE ROOMS WITHIN SCHOOLS 

6.9 LOCATING SAFE ROOMS TO MITIGATE 

THREATS

The building’s façade is its first real defense against the effects of 

a bomb and typically the weakest component that would be subjected to blast pressures. Although the response of specific glazed 

components5 is a function of the dimensions, make-up, and construction techniques, the conventionally glazed portions of the 

façade would shatter and inflict severe wounds when subjected 

to a 50-pound explosive detonation at a stand-off distance on the 

order of 200 feet. If the glazed elements are upgraded with a fragment retention film (FRF), the same façade element may be able 

to withstand a 50-pound explosive detonation at a stand-off distance on the order of 70 feet. Unreinforced masonry block walls 

are similarly vulnerable to collapse when subjected to a 50-pound 

threat at a stand-off distance of 50 feet; however, if these same 

walls are upgraded with a debris catching system, they may be able 

to sustain this same intensity explosive detonation at a stand-off 

distance on the order of 20 feet. If the weight of explosives were 

increased from 50 pounds to 500 pounds, the required stand-off 

distances to prevent severe wounds increases to 500 feet for conventional window glazing, 200 feet for window glazing treated 

with a FRF, 250 feet for unreinforced masonry block walls, and 

60 feet for masonry walls upgraded with a debris catching system. 

Based on these dimensions, it is apparent that substantial standoff distances are required for the unprotected structure and these 

distances may be significantly reduced through the use of debris 

mitigating retrofit systems. Furthermore, because blast loads diminish with distance and geometry of wave propagation relative 

to the loaded surface of the building, the larger threats at larger 

stand-off distances are likely to damage a larger percentage of façade 

elements than the more localized effects of smaller threats at 

shorter stand-off distances. Safe rooms that may be located within 

the school should, therefore, be located in windowless spaces or 

spaces in which the window glazing was upgraded with a FRF. 

5 Glazing refers to the glass make-up, either single pane or insulated double pane, that is used in 

a window system. 
SAFE ROOMS WITHIN SCHOOLS 6-21

Although small weights of explosives are not likely to produce 

significant blast loads on the roof, low-rise structures may be vulnerable to blast loadings resulting from large weights of explosives 

at large stand-off distances that may sweep over the top of the 

building. The blast pressures that may be applied to these roofs 

are likely to far exceed the conventional design loads and, unless the roof is a concrete deck or concrete slab structure, it may 

be expected to fail. There is little that can be done to increase 

Vulnerability to Domestic Explosive Threat

Throughout this primer, recommendations have been provided for schools that may be considered to be at high risk with the sound 

knowledge that schools are not currently considered to be at risk from potential terrorist attacks. However, it is important to note that 

proximity of a building to a high valued or iconic facility or its proximity to an industrial facility containing volatile chemicals may 

influence a structure’s risk to blast damage. In particular, if a school is located in close proximity to a U.S. courthouse, federal office 

building, or major financial institution, it may suffer collateral damage in the event the high-risk structure is the target of an explosive 

event. Similarly, if the school is located in close proximity to a grain elevator or industrial plant handling explosive materials, it may 

suffer collateral damage in the event of an accidental explosion. Although the increased vulnerability is a function of the stand-off 

distance and weight of explosive, large quantities of glass may fail in response to the detonation of a vehicle bomb. The risk to the 

protected structure is, therefore, a function of the risk of its being the intended target of an attack and the risk of being in close 

proximity to another structure that is the intended target of an attack. Schools in rural and suburban sites are typically sited on large 

parcels of land and surrounded by athletic fields and parking lots. This increases the stand-off distance from publicly traveled roadways. 

Schools in urban sites may be located in close proximity to prominent structures that are more likely to receive explosive threats and 

the stand-off distances to these threat locations may be sufficiently small to place the school building in jeopardy of significant collateral 

damage. School buildings that were located within several blocks of the World Trade Center were affected by the terrorist events. Urban 

school buildings should be evaluated on a case by case basis to determine their vulnerabilities and risks.

The history of domestic explosive events doesn’t justify the inspection of hand carried parcels into school buildings. Although metal 

detection and parcel searches are implemented within problem districts, these are primarily for other types of weapons or controlled 

substances. However, if an explosive device were to be carried into a school and detonated within the building, the resulting pressures 

would be confined and the effects of the explosion would be amplified. The blast waves and subsequent gas pressures would seek the 

path of least resistance as it seeks to equilibrate with the undisturbed atmosphere. Although the pipe or parcel bomb is small compared 

to the weights of explosives that might be transported in a vehicle, it would inflict injuries to occupants in close proximity and within 

direct line of sight of the detonation or located behind conventional nonstructural partitions. At short stand-off distances, these 

explosives could damage soft tissue such as lungs and eardrums and, at larger stand-off distances, these explosives could create debris 

that would impact the occupants. If a suspicious package is located within the building, the occupants would most likely be evacuated 

through exits that would lead them away from the potential threat. If, however, the occupants must be moved to a safe room, this 

space must be surrounded by a substantial structural wall or a reinforced masonry wall to limit the extent of debris.
6-22 SAFE ROOMS WITHIN SCHOOLS 

the roof’s resistance to blast loading that doesn’t require extensive renovation of the building structure. Therefore, safe rooms 

should be located at lower floors, away from the roof debris that 

may rain down in response to blast loading. 

The building’s lateral load resisting system, the structural frame 

or shear walls that resist wind and seismic loads, will be required 

to receive the blast loads that are applied to the exterior façade 

and transfer them to the building’s foundation. This load path is 

typically through the floor slabs that act as diaphragms and interconnect the different lateral resisting elements. The lateral load 

resisting system for a school building depends, to a great extent, 

on the type of construction and region. In many cases, low-rise 

buildings do not receive substantial wind and seismic forces and, 

therefore, do not require substantial lateral load resisting systems. 

Because blast loads diminish with distance, a package sized explosive threat is likely to locally overwhelm the façade, thereby 

limiting the force that may be transferred to the lateral load resisting system. However, the intensity of the blast loads that may 

be applied to the building could exceed the design limits for most 

conventional school construction. As a result, the building is likely 

to be subjected to large inelastic deformations that may produce 

severe cracks to the structural and nonstructural partitions. There 

is little that can be done to upgrade the existing school structure 

to make it more flexible in response to a blast loading that doesn’t 

require extensive renovation of the building. Safe rooms should, 

therefore, be located close to the interior shear walls or reinforced 

masonry walls in order to provide maximum structural support in 

response to these uncharacteristically large lateral loads.

In addition to the hazard of impact by façade debris propelled 

into the building or roof damage that may rain down, the occupants may also be vulnerable to much heavier debris resulting 

from structural damage. Progressive collapse occurs when an initiating localized failure causes adjoining members to be overloaded 

and fail, resulting in an extent of damage that is disproportionate 

to the originating region of localized failure. The initiating localized failure may result from a sufficiently sized parcel bomb that 
SAFE ROOMS WITHIN SCHOOLS 6-23

is in contact with a critical structural element or from a vehicle 

sized bomb that is located at a short distance from the structure. 

However, a large explosive device at a large stand-off distance is 

not likely to selectively cause a single structural member to fail; 

any damage that results from this scenario is more likely to be 

widespread and the ensuing collapse cannot be considered progressive. Although progressive collapse is not typically an issue for 

buildings three stories or shorter, transfer girders or precast construction may produce structural systems that are not tolerant of 

localized damage conditions. The columns that support transfer 

girders and the transfer girders themselves may be critical to 

the stability of a large area of floor space. Similarly, precast construction that relies on individual structural panels may not be 

sufficiently tied together to resist the localized damage or large 

structural deformations that may result from an explosive detonation. As a result, safe rooms should not be located on a structure 

that is either supported by or underneath a structure that is 

supported by transfer girders unless the building is evaluated 

by a licensed professional engineer. The connection details for 

multi-story precast structures should also be evaluated before the 

building is used to house a safe room. 

Nonstructural building components (e.g., piping, ducts, lighting 

units, and conduits) that are located within safe rooms must be 

sufficiently tied back to 

a competent structure 

to prevent failure of the 

services and the hazard of 

falling debris. To mitigate 

the effects of in-structure 

shock that may result from 

the infilling of blast pressures through damaged 

windows, the nonstructural 

systems should be located 

below the raised floors or 

tied to the ceiling slabs 

with seismic restraints.

Safe rooms in existing school buildings should be selected to provide the space required to 

accommodate the school population; should be centrally located to allow quick access from 

any location within the building; should be enclosed with fragment mitigating partitions or 

façade; and should be within robust structural systems that will resist collapse. These large 

spaces are best located at the lower floors, away from a lightweight roof and exterior 

glazing elements. If such a space does not exist within the existing school structure, the 

available spaces may be upgraded to achieve as many of these attributes as possible. This 

will involve the treatment of the exterior façade with fragment mitigating films, blast 

curtains, debris catch systems, spray-on applications of elasto-polymers to unreinforced 

masonry walls, hardening of select columns and slabs with composite fiber wraps, and 

steel jackets or concrete encasements. Fragment mitigating and structural upgrades and 

recommendations for blast protection are discussed in the following sections. 
6-24 SAFE ROOMS WITHIN SCHOOLS 

6.10 FRAGMENT MITIGATING UPGRADES

The conversion of existing construction to provide blast-resistant protection requires upgrades to the most fragile or brittle 

elements enclosing the safe room. Failure of the glazed portion 

of the façade represents the greatest hazard to the occupants. 

Therefore, the exterior glazed elements of the school façade 

and, in particular, the glazed elements of the designated safe 

rooms, should be protected with a FRF, also commonly known as 

anti-shatter film (ASF), “shatter-resistant window film” (SRWF), 

or “security film.” These materials consist of a laminate that will 

improve post-damage performance of existing windows. Applied 

to the interior face of glass, ASF holds the fragments of broken 

glass together in one sheet, thus reducing the projectile hazard of 

flying glass fragments. See FEMA 426 Reference Manual to Mitigate 

Potential Terrorist Attacks Against Buildings for more information.

Most ASFs are made from polyester-based materials and coated 

with adhesives. They are available as clear, with minimal effects to 

the optical characteristics of the glass, and tinted, which provide 

a variety of aesthetic and optical enhancements and can increase 

the effectiveness of existing heating/cooling systems. Most films 

are designed with solar inhibitors to screen out ultraviolet (UV) 

rays and are available treated with an abrasion resistant coating 

that can prolong the life of tempered glass.6 However, over time, 

the UV absorption damages the film and degrades its effectiveness.

According to published reports, testing has shown that a 7-mil 

thick film, or specially manufactured 4-mil thick film, is the minimum thickness that is required to provide hazard mitigation from 

blast. Therefore, a 4-mil thick ASF should be utilized only if it has 

demonstrated, through explosive testing, that it is capable of providing the desired hazard level response. 

The application of security film must, at a minimum, cover the 

clear area of the window. The clear area is defined as the portion 

of the glass unobstructed by the frame. This minimum applica6 Abrasions on the faces of tempered glass reduce the glass strength.
SAFE ROOMS WITHIN SCHOOLS 6-25

tion, termed daylight installation, is commonly used for retrofitting 

windows. By this method, the film is applied to the exposed glass 

without any means of attachment or capture within the frame. 

Application of the film to the edge of the glass panel, thereby extending the film to cover the glass within the bite, is called an edge 

to edge installation and is often used in dry glazing installations. 

Other methods of retrofit application may improve the film performance, thereby reducing the hazard; however, these are typically 

more expensive to install, especially in a retrofit situation.

Although a film may be effective in keeping glass fragments together, it may not be particularly effective in retaining the glass in 

the frame. ASF is most effective when it is used with a blast tested 

anchorage system. Such a system prevents the failed glass from exiting the frame.

The wet glazed installation, a system where the film is positively 

attached to the frame, offers more protection than the daylight 

installation. This system of attaching the film to the frame reduces 

glass fragmentation entering the building. The wet glazing system 

utilizes a high strength liquid sealant, such as silicone, to attach 

the glazing system to the frame. This method is more costly than 

the daylight installation.

Securing the film to the frame with a mechanically connected 

anchorage system further reduces the likelihood of the glazing 

system exiting the frame. Mechanical attachment includes anchoring methods that employ screws and/or batten strips that 

anchor the film to the frame along two or four sides. The mechanical attachment method can be less aesthetically pleasing when 

compared to wet glazing because additional framework is necessary and is more expensive than the wet glazed installation.

Window framing systems and their anchorage must be capable of 

transferring the blast loads to the surrounding walls. Unless the 

frames and anchorages are competent, the effectiveness of the 

attached films will be limited. Similarly, the walls must be able to withstand the blast loads that are directly applied to them and accept the 
6-26 SAFE ROOMS WITHIN SCHOOLS 

blast loads that are transferred by the windows. The strength of these 

walls may limit the effectiveness of the glazing upgrades.

If a major rehabilitation of the façade is required to improve the 

mechanical characteristics of the building envelope, a laminated 

glazing replacement is recommended. Laminated glass consists 

of two or more pieces of glass permanently bonded together by 

a tough plastic interlayer made of polyvinyl butyral (PVB) resin. 

After being sealed together, the glass “sandwich” behaves as a 

single unit. Annealed, heat strengthened, tempered glass, or 

polycarbonate glazing can be mixed and matched between layers 

of laminated glass in order to design the most effective lite for a 

given application. When fractured, fragments of laminated glass 

tend to adhere to the PVB interlayer, rather than falling free and 

potentially causing injury.

Laminated glass can be expected to last as long as ordinary glass 

provided it is not broken or damaged in any way. It is very important that laminated glass is correctly installed in order to ensure 

long life. Regardless of the degree of protection required from 

the window, laminated glass needs to be installed with adequate 

sealant to prevent water from coming in contact with the edges 

of the glass. A structural sealant will adhere the glazing to the 

frame and allow the PVB interlayer to develop its full membrane 

capacity. Similar to attached film upgrades, the window frames and 

anchorages must be capable of transferring the blast loads to the 

surrounding walls.

Blast curtains are made from a variety of materials, including a 

warp knit fabric or a polyethylene fiber. The fiber can be woven 

into a panel as thin as 0.029 inch that weighs less than 1.5 ounces 

per square foot. This fact dispels the myth that blast curtains are 

heavy sheets of lead that completely obstruct a window opening 

and eliminate all natural light from the interior of a protected 

building. The blast curtains are affixed to the interior frame of 

a window opening and essentially catch the glass fragments produced by a blast wave. The debris is then deposited on the floor at 

the base of the window. Therefore, the use of these curtains does 
SAFE ROOMS WITHIN SCHOOLS 6-27

not eliminate the possibility of glass fragments penetrating the interior of the occupied space, but instead limits the travel distance 

of the airborne debris. Overall, the hazard level to occupants is 

significantly reduced by the implementation of the blast curtains. 

However, a person sitting directly adjacent to a window outfitted 

with a blast curtain may still be injured by shards of glass in the 

event of an explosion.

The main components of any blast curtain system are the curtain 

itself, the attachment mechanism by which the curtain is affixed to 

the window frame, and either a trough or other retaining mechanism at the base of the window to hold the excess curtain material. 

The blast curtain with curtain rod attachment and sill trough 

differ largely from one manufacturer to the next. The curtain 

fabric, material properties, method of attachment, and manner in 

which they operate all vary, thereby providing many options within 

the overall classification of blast curtains. This fact makes blast curtains applicable in many situations.

Blast curtains differ from standard curtains in that they do not 

open and close in the typical manner. Although blast curtains 

are intended to remain in a closed position at all times, they may 

be pulled away from the window to allow for cleaning, blind or 

shade operation, or occupant egress in the case of fire. However, 

the curtains can be rendered ineffective if installed such that easy 

access would provide opportunity for occupants to defeat their 

operation. The color and openness factor of the fabric contributes 

to the amount of light that is transmitted through the curtains and 

the see-through visibility of the curtains. Although the color and 

weave of these curtains may be varied to suit the aesthetics of the 

interior décor, the appearance of the windows is altered by the 

presence of the curtains.

The curtains may either be anchored at the top and bottom of 

the window frame or anchored at the top only and outfitted with 

a weighted hem. The curtain needs to be extra long with the surplus either wound around a dynamic tension retainer or stored in 

a reservoir housing. When an explosion occurs, the curtain feeds 
6-28 SAFE ROOMS WITHIN SCHOOLS 

out of the receptacle to absorb the force of the flying glass fragments. The effectiveness of the blast curtains relies on their use 

and no protection is provided when these curtains are pulled away 

from the glazing. 

Rigid catch bar systems have been designed and tested as a means 

of increasing the effectiveness of laminated window upgrades. 

Laminated glazing is designed to hold the glass shards together as 

the window is damaged; however, unless the window frames and 

attachments are upgraded as well to withstand the capacity of the 

glazing, this retrofit will not prevent the entire sheet from flying 

free of the window frames. The rigid catch bars intercept the 

laminated glass and disrupt their flight; however, they are limited 

in their effectiveness, tending to break the dislodged façade materials into smaller projectiles. 

Rigid catch bar systems collect huge forces upon impact and require substantial anchorage into a very substantial structure to 

prevent failure. If either the attachments or the supporting structure are incapable of restraining the forces, the catch system will 

be dislodged and become part of the debris. Alternatively, the debris may be sliced by the rigid impact and the effectiveness of the 

catch bar will be severely reduced. 

Flexible catch bars can be designed to absorb a significant amount 

of the energy upon impact, thereby keeping the debris intact and 

impeding their flight. These systems may be designed to effectively repel the debris and inhibit their flight into the occupied 

spaces. These systems may be designed to repel the debris from 

the failed glazing as well as the walls in which the windows are 

mounted. The design of the debris restraint system must be strong 

enough to withstand the momentum transferred upon impact 

and the connections must be capable of transferring the forces 

to the supporting slabs and spandrel beams. However, under no 

circumstances can the design of the restraint system add significant amounts of mass to the structure that may be dislodged and 

present an even greater risk to the occupants of the building.
SAFE ROOMS WITHIN SCHOOLS 6-29

Cables are extensively used to absorb significant amounts of energy upon impact and their flexibility makes them easily adaptable 

to many situations. The diameter of the cable, the spacing of the 

strands, and the means of attachment are all critical in designing 

an effective catch system. These catch cable concepts have been 

used by protective design window manufacturers as restraints for 

laminated lites. The use of cable systems has long been recognized 

as an effective means of stopping massive objects moving at high 

velocity. To confirm the adequacy of the cable catch system to restrain the debris resulting from an explosive event, an analytical 

simulation or a physical test is required.

High performance energy absorbing cable catcher systems retain glass and frame fragments and limit the force transmitted to 

the supporting structure. These commercially available retrofit 

products consist of a series of 1⁄4-inch diameter stainless steel 

cables connected with a shock-absorbing device to an aluminum 

box section, which is attached to the jambs, the underside of the 

header, and the topside of the sill. The energy absorbing characteristics allow the catch systems to be attached to relatively weakly 

constructed walls without the need for additional costly structural 

reinforcement. To reduce the possibility of slicing the laminated 

glass, the cable may either be sheathed in a tube or an aluminum 

strip may be affixed to the glass directly behind the cable.

Unreinforced CMU walls provide limited protection against 

air-blast due to explosions. When subjected to overload from airblast, brittle unreinforced CMU walls will fail and the debris will 

be propelled into the interior of the structure, possibly causing 

severe injury or death to the occupants. This wall type has been 

prohibited for new construction where protection against explosive threats is required. Existing unreinforced CMU walls may be 

retrofitted with a sprayed-on polymer coating to improve their airblast resistance. This innovative retrofit technique takes advantage 

of the toughness and resiliency of modern polymer materials to 

effectively deform and dissipate the blast energy while containing 

the shattered wall fragments. Although the sprayed walls may 

shatter in a blast event, the elastomer material remains intact and 

contains the debris.
6-30 SAFE ROOMS WITHIN SCHOOLS 

The blast mitigation retrofit for unreinforced CMU walls consists 

of an interior and optional exterior layer of polyurea applied to 

exterior walls and ceilings. The polyurea provides a ductile and 

resilient membrane that catches and retains secondary fragmentation from the existing concrete block as it breaks apart in response 

to an air-blast wave. These fragments, if allowed to enter the occupied space, are capable of producing serious injury and death to 

occupants of the structure.

In lieu of the elastomer, an aramid (Geotextile) debris catching 

system may be attached to the structure by means of plates bolted 

through the floor and ceiling slabs. Similar to the elastomer retrofit, the aramid layer does not strengthen the wall; instead, it 

restrains the debris that would otherwise be hurled into the occupied spaces.

6.11 STRUCTURAL UPGRADES

It may not be possible for existing construction to be retrofitted 

to limit the extent of collapse to one floor on either side of the 

failed column. If the members are retrofitted to develop catenary 

behavior, the adjoining bays must be upgraded to resist the large 

lateral forces associated with this mode of response. This may 

require more extensive retrofit than is either feasible or desirable. 

In such a situation, it may be desirable to isolate the collapsed region rather than risk propagating the collapse to adjoining bays. 

The retrofit of existing structures to protect against a potential 

progressive collapse resulting from the detonation of a terrorist 

explosive threat may, therefore, best be achieved through the 

localized hardening of vulnerable columns. These columns need 

only be upgraded to a level of resistance that balances the capacities of all adjacent structural elements. At greater blast intensities, 

the resulting damage would be extensive and termed global collapse rather than progressive collapse. Attempts to upgrade the 

structure to conform to the alternate path approach will be invasive and potentially counterproductive. Care must be taken not to 

weaken a structure in the attempt to make it more robust.
SAFE ROOMS WITHIN SCHOOLS 6-31

Conventionally designed columns may be vulnerable to the effects 

of explosives, particularly when placed in contact with their surface. Stand-off elements, in the form of partitions and enclosures, 

may be designed to guarantee a minimum stand-off distance; 

however, this alone may not be sufficient. Additional resistance 

may be provided to reinforced concrete structures by means of 

a steel jacket or a carbon fiber wrap that effectively confines the 

concrete core, thereby increasing the confined strength and shear 

capacity of the column, and holds the rubble together to permit it 

to continue carrying the axial loads. The capacity of steel flanged 

columns may be increased with a reinforced concrete encasement 

that adds mass to the steel section and protects the relatively thin 

flange sections. The details for these retrofits must be designed to 

resist the specific weight of explosives and stand-off distance. 

The floor slabs are typically designed to resist downward gravity 

loading and have limited capacity to resist uplift pressures or 

the upward deformations experienced during a load reversal. 

Therefore, floor slabs that may be subjected to significant uplift 

pressures, such that they overcome the gravity loads and subject 

the slabs to reversals in curvature, require additional reinforcement. If the slab does not contain this tension reinforcement, it must 

be supplemented with a lightweight carbon fiber application that 

may be bonded to the surface at the critical locations. Carbon 

fiber reinforcing mats bonded to the top surface of slabs would 

strengthen the floors for upward loading and reduce the likelihood of slab collapse from blast infill uplift pressures as well as 

internal explosions in mailrooms or other susceptible regions. 

This lightweight high tensile strength material will supplement 

the limited capacity of the concrete to resist these unnatural 

loading conditions. An alternative approach may be to notch 

grooves in the top of concrete slabs and epoxy carbon fiber rods 

into grooves; although this approach may offer a greater capacity, it is much more invasive and has not been evaluated with 

explosive testing. 
6-32 SAFE ROOMS WITHIN SCHOOLS

RECOMMENDATIONS FOR BLAST PROTECTION 

The following actions are recommended for blast protection:

❍	 Increase the level of protection against an external detonation by applying any 

one of the fragment mitigating options summarized above to a renovated school 

gymnasium or auditorium safe room. The effectiveness of these measures will 

depend on advanced notification of a suspicious device and the distance from the 

explosive source.

❍	 Develop plans, procedures, and training for sheltering in place as a protective action 

against a remote explosive threat. To support this protective measure, define a rapid 

notification system (public address system) and safe evacuation routes.

❍	 Develop security procedures specific to entry screening for suspicious objects to 

reduce vulnerability to internal detonation. However, the decision to implement 

these procedures should be made on a case by case basis following a thorough risk 

analysis for the facility.
ACRONYMS A

ACRONYMS A-1

A

ADAAG Americans with Disabilities Act Accessibility 

Guidelines

AED automated external defibrillator

ANFO ammonium nitrate and fuel oil

APS apartment protected space

ASF anti-shatter film

ASZM-TEDA copper-silver-zinc-molybdenum-triethylenediamine

AT antiterrorism

ATF Bureau of Alcohol, Tobacco, and Firearms

B

BPL bound with pitch-low

BW biological warfare

C

CBR chemical, biological, or radiological

CCTV closed circuit television

CDC Centers for Disease Control and Prevention

CFD Computational Fluid Dynamics

cfm cubic feet per minute

CMU concrete masonry unit
A-2 ACRONYMS 

CPR cardiopulmonary resuscitation

CPTED Crime Prevention Through Environmental Design

CWA chemical warfare agent

D

DHS Department of Homeland Security

DOC Department of Commerce

DoD Department of Defense

DOE Department of Education

DOJ Department of Justice

DOS Department of State

E

EP&R Directorate of Emergency Preparedness and 

Response (DHS)

F

FBI Federal Bureau of Investigation

FEMA Federal Emergency Management Agency

FPS floor protected space

FRF fragment retention film
ACRONYMS A-3

G

GC/MS gas chromatograph/mass spectrometer

GIS Geographic Information System

GSA General Services Administration

H

HazMat hazardous materials

HEGA high-efficiency gas adsorber

HEPA high-efficiency particulate air

HSO Homeland Security Office

HVAC heating, ventilation, and air conditioning

I

IAQ indoor air quality

ID identification

IDF Israeli Defense Fund

IMS ion mobility spectrometry

ISC Interagency Security Committee

IT information technology

iwg inch water gauge

M

mph miles per hour 
A-4 ACRONYMS 

N

NACCT National Advisory Committee on Children and 

Terrorism

NAVFAC Naval Facilities Command

NFPA National Fire Protection Association

NFPC National Fire Protection Code

NIOSH National Institute for Occupational Safety and 

Health

O

OC oleoresin capsicum

P

PIO Public Information Officer

psi pounds per square inch

pvb polyvinyl butyral

S

SAW surface acoustic wave

SRWF shatter-resistant window film
ACRONYMS A-5

T

TEDA triethylenediamine

TIC toxic industrial chemical

TIM toxic industrial material

TNT trinitrotoluene

U

UFAS Uniform Federal Accessibility Standards

UFC Unified Facilities Criteria

U.K. United Kingdom

UPS uninterrupted power supply

U.S. United States

USACE U.S. Army Corps of Engineers

UV ultraviolet

V

VA Department of Veterans Affairs

GENERAL GLOSSARY B

GENERAL GLOSSARY B-1

This appendix contains some terms that do not actually 

appear in this manual. They have been included to present a 

comprehensive list that pertains to this series of publications.

A

Access control. Any combination of barriers, gates, electronic 

security equipment, and/or guards that can deny entry to 

unauthorized personnel or vehicles.

Access control point. A station at an entrance to a building or a 

portion of a building where identification is checked and people 

and hand-carried items are searched.

Access controls. Procedures and controls that limit or detect 

access to minimum essential infrastructure resource elements 

(e.g., people, technology, applications, data, and/or facilities), 

thereby protecting these resources against loss of integrity, 

confidentiality, accountability, and/or availability.

Accountability. The explicit assignment of responsibilities for 

oversight of areas of control to executives, managers, staff, 

owners, providers, and users of minimum essential infrastructure 

resource elements.

Active vehicle barrier. An impediment placed at an access 

control point that may be manually or automatically deployed in 

response to detection of a threat.

Aerosol. Fine liquid or solid particles suspended in a gas (e.g., fog 

or smoke).

Aggressor. Any person seeking to compromise a function or 

structure.

Airborne contamination. Chemical or biological agents 

introduced into and fouling the source of supply of breathing or 

conditioning air.
B-2 GENERAL GLOSSARY 

Antiterrorism (AT). Defensive measures used to reduce the 

vulnerability of individuals, forces, and property to terrorist acts.

Area lighting. Lighting that illuminates a large exterior area.

Assessment. The evaluation and interpretation of measurements 

and other information to provide a basis for decision-making.

Asset. A resource of value requiring protection. An asset can be 

tangible (e.g., people, buildings, facilities, equipment, activities, 

operations, and information) or intangible (e.g., processes or a 

company’s information and reputation).

Asset protection. Security program designed to protect 

personnel, facilities, and equipment, in all locations and 

situations, accomplished through planned and integrated 

application of combating terrorism, physical security, operations 

security, and personal protective services, and supported by 

intelligence, counterintelligence, and other security programs.

Asset value. The degree of debilitating impact that would be 

caused by the incapacity or destruction of an asset.

Attack. A hostile action resulting in the destruction, injury, or 

death to the civilian population, or damage or destruction to 

public and private property.

B

Balanced magnetic switch. A door position switch utilizing a 

reed switch held in a balanced or center position by interacting 

magnetic fields when not in alarm condition.

Ballistics attack. An attack in which small arms (e.g., pistols, 

submachine guns, shotguns, and rifles) are fired from a distance 

and rely on the flight of the projectile to damage the target.

Barbed tape or concertina. A coiled tape or coil of wires with wire 

barbs or blades deployed as an obstacle to human trespass or 

entry into an area.
GENERAL GLOSSARY B-3

Barbed wire. A double strand of wire with four-point barbs 

equally spaced along the wire deployed as an obstacle to human 

trespass or entry into an area.

Barcode. A black bar printed on white paper or tape that can be 

easily read with an optical scanner.

Biological agents. Living organisms or the materials derived from 

them that cause disease in or harm to humans, animals, or plants 

or cause deterioration of material. Biological agents may be used 

as liquid droplets, aerosols, or dry powders.

Blast curtains. Heavy curtains made of blast-resistant materials 

that could protect the occupants of a room from flying debris.

Blast-resistant glazing. Window opening glazing that is resistant to 

blast effects because of the interrelated function of the frame and 

glazing material properties frequently dependent upon tempered 

glass, polycarbonate, or laminated glazing.

Blast vulnerability envelope. The geographical area in which an 

explosive device will cause damage to assets.

Bollard. A vehicle barrier consisting of a cylinder, usually made 

of steel and sometimes filled with concrete, placed on end in the 

ground and spaced about 3 feet apart to prevent vehicles from 

passing, but allowing entrance of pedestrians and bicycles.

Building hardening. Enhanced construction that reduces 

vulnerability to external blast and ballistic attacks.

Building separation. The distance between closest points on the 

exterior walls of adjacent buildings or structures.

C 

Cable barrier. Cable or wire rope anchored to and suspended off 

the ground or attached to chain-link fence to act as a barrier to 

moving vehicles.

Chemical agent. A chemical substance that is intended to kill, 
B-4 GENERAL GLOSSARY 

seriously injure, or incapacitate people through physiological 

effects. Generally separated by severity of effect (e.g., lethal, 

blister, and incapacitating).

Clear zone. An area that is clear of visual obstructions and 

landscape materials that could conceal a threat or perpetrator.

Closed circuit television (CCTV). An electronic system of 

cameras, control equipment, recorders, and related apparatus 

used for surveillance or alarm assessment.

Collateral damage. Injury or damage to assets that are not the 

primary target of an attack.

Combating terrorism. The full range of federal programs and 

activities applied against terrorism, domestically and abroad, 

regardless of the source or motive.

Community. A political entity that has the authority to adopt and 

enforce laws and ordinances for the area under its jurisdiction. In 

most cases, the community is an incorporated town, city, township, 

village, or unincorporated area of a county; however, each state 

defines its own political subdivisions and forms of government.

Components and cladding. Elements of the building envelope 

that do not qualify as part of the main wind-force resisting system.

Confidentiality. The protection of sensitive information against 

unauthorized disclosure and sensitive facilities from physical, 

technical, or electronic penetration or exploitation.

Consequence Management. Measures to protect public health 

and safety, restore essential government services, and provide 

emergency relief to governments, businesses, and individuals 

affected by the consequences of terrorism. State and local 

governments exercise the primary authority to respond to the 

consequences of terrorism.

Contamination. The undesirable deposition of a chemical, 

biological, or radiological material on the surface of structures, 

areas, objects, or people.

Control center. A centrally located room or facility staffed by 
GENERAL GLOSSARY B-5

personnel charged with the oversight of specific situations and/

or equipment.

Controlled area. An area into which access is controlled or 

limited. It is that portion of a restricted area usually near 

or surrounding a limited or exclusion area. Correlates with 

exclusion zone.

Controlled lighting. Illumination of specific areas or sections.

Controlled perimeter. A physical boundary at which vehicle 

and personnel access is controlled at the perimeter of a site. 

Access control at a controlled perimeter should demonstrate the 

capability to search individuals and vehicles.

Conventional construction. Building construction that is not 

specifically designed to resist weapons, explosives, or chemical, 

biological, and radiological effects. Conventional construction 

is designed only to resist common loadings and environmental 

effects such as wind, seismic, and snow loads.

Coordinate. To advance systematically an exchange of 

information among principals who have or may have a need to 

know certain information in order to carry out their roles in a 

response.

Counterintelligence. Information gathered and activities 

conducted to protect against: espionage, other intelligence 

activities, sabotage, or assassinations conducted for or on behalf 

of foreign powers, organizations, or persons; or international 

terrorist activities, excluding personnel, physical, document, and 

communications security programs.

Counterterrorism (CT). Offensive measures taken to prevent, 

deter, and respond to terrorism.

Covert entry. Attempts to enter a facility by using false credentials 

or stealth.

Crash bar. A mechanical egress device located on the interior side 

of a door that unlocks the door when pressure is applied in the 

direction of egress.
B-6 GENERAL GLOSSARY 

Crime Prevention Through Environmental Design (CPTED). A 

crime prevention strategy based on evidence that the design and 

form of the built environment can influence human behavior. 

CPTED usually involves the use of three principles: natural 

surveillance (by placing physical features, activities, and people 

to maximize visibility); natural access control (through the 

judicial placement of entrances, exits, fencing, landscaping, and 

lighting); and territorial reinforcement (using buildings, fences, 

pavement, signs, and landscaping to express ownership).

Crisis Management (CM). The measures taken to identify, 

acquire, and plan the use of resources needed to anticipate, 

prevent, and/or resolve a threat or act of terrorism.

Critical assets. Those assets essential to the minimum operations 

of the organization, and to ensure the health and safety of the 

general public.

Critical infrastructure. Primary infrastructure systems (e.g., 

utilities, telecommunications, transportation, etc.) whose 

incapacity would have a debilitating impact on the school’s ability 

to function.

D

Damage assessment. The process used to appraise or determine 

the number of injuries and deaths, damage to public and private 

property, and the status of key facilities and services (e.g., schools, 

hospitals and other health care facilities, fire and police stations, 

communications networks, water and sanitation systems, utilities, 

and transportation networks) resulting from a manmade or 

natural disaster.

Data gathering panel. A local processing unit that retrieves, 

processes, stores, and/or acts on information in the field.

Debris-catching system. Blast wallpaper, fragmentation blankets, 

or any similar system applied to the inside of a building’s 
GENERAL GLOSSARY B-7

exterior walls. Debris-catching systems are often made of Kevlar 

or geotextile material and are designed to collect wall material 

debris in the event of an external explosion and to shield 

occupants from injuries.

Decontamination. The reduction or removal of a chemical, 

biological, or radiological material from the surface of a 

structure, area, object, or person.

Defense layer. Building design or exterior perimeter barriers 

intended to delay attempted forced entry.

Defensive measures. Protective measures that delay or prevent 

attack on an asset or that shield the asset from weapons, 

explosives, and CBR effects. Defensive measures include site work 

and building design.

Design Basis Threat (DBT). The threat (e.g., tactics and 

associated weapons, tools, or explosives) against which assets 

within a building must be protected and upon which the security 

engineering design of the school is based.

Design constraint. Anything that restricts the design options for 

a protective system or that creates additional problems for which 

the design must compensate.

Design opportunity. Anything that enhances protection, reduces 

requirements for protective measures, or solves a design problem.

Design team. A group of individuals from various engineering and 

architectural disciplines responsible for the protective system design.

Disaster. An occurrence of a natural catastrophe, technological 

accident, or human-caused event that has resulted in severe 

property damage, deaths, and/or multiple injuries.

Domestic terrorism. The unlawful use, or threatened use, of force 

or violence by a group or individual based and operating entirely 

within the United States or Puerto Rico without foreign direction 

committed against persons or property to intimidate or coerce a 

government, the civilian population, or any segment thereof in 

furtherance of political or social objectives.
B-8 GENERAL GLOSSARY 

Dose rate (radiation). A general term indicating the quantity 

(total or accumulated) of ionizing radiation or energy absorbed 

by a person or animal, per unit of time.

Dosimeter. An instrument for measuring and registering total 

accumulated exposure to ionizing radiation.

Duress alarm devices. Also known as panic buttons, these devices 

are designated specifically to initiate a panic alarm. 

E

Effective stand-off distance. A stand-off distance at which the 

required level of protection can be shown to be achieved through 

analysis or can be achieved through building hardening or other 

mitigating construction or retrofit.

Electronic Entry Control Systems (EECS). Electronic devices that 

automatically verify authorization for a person to enter or exit a 

controlled area.

Electronic Security System (ESS). An integrated system that 

encompasses interior and exterior sensors, closed circuit 

television systems for assessment of alarm conditions, Electronic 

Entry Control Systems, data transmission media, and alarm 

reporting systems for monitoring, control, and display of various 

alarm and system information.

Emergency. Any natural or human-caused situation that results in 

or may result in substantial injury or harm to the population or 

substantial damage to or loss of property.

Emergency Environmental Health Services. Services required to 

correct or improve damaging environmental health effects on 

humans, including inspection for food contamination, inspection 

for water contamination, and vector control; providing for sewage 

and solid waste inspection and disposal; cleanup and disposal of 

hazardous materials; and sanitation inspection for emergency 

shelter facilities.
GENERAL GLOSSARY B-9

Emergency Medical Services (EMS). Services including personnel, 

facilities, and equipment required to ensure proper medical care 

for the sick and injured from the time of injury to the time of 

final disposition, including medical disposition within a hospital, 

temporary medical facility, or special care facility; release from 

the site; or declared dead. Further, Emergency Medical Services 

specifically include those services immediately required to ensure 

proper medical care and specialized treatment for patients in a 

hospital and coordination of related hospital services.

Emergency Operations Center (EOC). The protected site from which 

state and local civil government officials coordinate, monitor, and 

direct emergency response activities during an emergency.

Emergency Operations Plan (EOP). A document that describes 

how people and property will be protected in disaster and disaster 

threat situations; details who is responsible for carrying out 

specific actions; identifies the personnel, equipment, facilities, 

supplies, and other resources available for use in the disaster; and 

outlines how all actions will be coordinated.

Emergency Public Information (EPI). Information that is disseminated primarily in anticipation of an emergency or at the actual 

time of an emergency and, in addition to providing information, 

frequently directs actions, instructs, and transmits direct orders.

Entry control point. A continuously or intermittently manned 

station at which entry to sensitive or restricted areas is controlled.

Equipment closet. A room where field control equipment such as 

data gathering panels and power supplies are typically located.

Evacuation. Organized, phased, and supervised dispersal of 

people from dangerous or potentially dangerous areas.

Evacuation, mandatory or directed. This is a warning to persons 

within the designated area that an imminent threat to life and 

property exists and individuals MUST evacuate in accordance 

with the instructions of local officials.

Evacuation, spontaneous. Residents or citizens in the threatened 

areas observe an emergency event or receive unofficial word of 
B-10 GENERAL GLOSSARY 

an actual or perceived threat and, without receiving instructions 

to do so, elect to evacuate the area. Their movement, means, and 

direction of travel are unorganized and unsupervised.

Evacuation, voluntary. This is a warning to persons within a 

designated area that a threat to life and property exists or is likely 

to exist in the immediate future. Individuals issued this type 

of warning or order are NOT required to evacuate; however, it 

would be to their advantage to do so.

Evacuees. All persons removed or moving from areas threatened 

or struck by a disaster.

Exclusion area. A restricted area containing a security interest. 

Uncontrolled movement permits direct access to the item. See 

controlled area and limited area.

Exclusion zone. An area around an asset that has controlled entry 

with highly restrictive access. See controlled area.

F

Federal Coordinating Officer (FCO). The person appointed 

by the FEMA Director to coordinate federal assistance in a 

Presidentially declared emergency or major disaster.

Federal Response Plan (FRP). The FRP establishes a process and 

structure for the systematic, coordinated, and effective delivery 

of federal assistance to address the consequences of any major 

disaster or emergency.

Fence protection. An intrusion detection technology that detects 

a person crossing a fence by various methods such as climbing, 

crawling, cutting, etc.

Fence sensor. An exterior intrusion detection sensor that 

detects aggressors as they attempt to climb over, cut through, or 

otherwise disturb a fence.

Field of view. The visible area in a video picture.
GENERAL GLOSSARY B-11

First responder. Local police, fire, and emergency medical 

personnel who first arrive on the scene of an incident and take 

action to save lives, protect property, and meet basic human needs.

Forced entry. Entry to a denied area achieved through force to create 

an opening in fence, walls, doors, etc., or to overpower guards.

Fragment retention film (FRF). A thin, optically clear film applied 

to glass to minimize the spread of glass fragments when the glass 

is shattered.

Frangible construction. Building components that are designed 

to fail to vent blast pressures from an enclosure in a controlled 

manner and direction.

G

Glare security lighting. Illumination projected from a secure 

perimeter into the surrounding area, making it possible to see 

potential intruders at a considerable distance while making it 

difficult to observe activities within the secure perimeter.

Glazing. A material installed in a sash, ventilator, or panes (e.g., 

glass, plastic, etc., including material such as thin granite installed 

in a curtain wall).

Governor’s Authorized Representative (GAR). The person 

empowered by the Governor to execute, on behalf of the State, 

all necessary documents for disaster assistance.

H

Hazard. A source of potential danger or adverse condition.

Hazard mitigation. Any action taken to reduce or eliminate the 

long-term risk to human life and property from hazards. The 

term is sometimes used in a stricter sense to mean cost-effective 
B-12 GENERAL GLOSSARY 

measures to reduce the potential for damage to a facility or 

facilities from a disaster event.

Hazardous material (HazMat). Any substance or material 

that, when involved in an accident and released in sufficient 

quantities, poses a risk to people’s health, safety, and/or 

property. These substances and materials include explosives, 

radioactive materials, flammable liquids or solids, combustible 

liquids or solids, poisons, oxidizers, toxins, and corrosive 

materials.

High-hazard areas. Geographic locations that, for planning 

purposes, have been determined through historical experience 

and vulnerability analysis to be likely to experience the effects 

of a specific hazard (e.g., hurricane, earthquake, hazardous 

materials accident, etc.), resulting in vast property damage and 

loss of life.

High-risk target. Any material resource or facility that, because of 

mission sensitivity, ease of access, isolation, and symbolic value, 

may be an especially attractive or accessible terrorist target.

Human-caused hazard. Human-caused hazards are technological 

hazards and terrorism. They are distinct from natural hazards 

primarily in that they originate from human activity. Within the 

military services, the term threat is typically used for humancaused hazard. See definitions of technological hazards and 

terrorism for further information.

I

International terrorism. Violent acts or acts dangerous to 

human life that are a violation of the criminal laws of the 

United States or any state, or that would be a criminal violation 

if committed within the jurisdiction of the United States or any 

state. These acts appear to be intended to intimidate or coerce 

a civilian population, influence the policy of a government by 

intimidation or coercion, or affect the conduct of a government 
GENERAL GLOSSARY B-13

by assassination or kidnapping. International terrorist acts occur 

outside the United States, or transcend national boundaries in 

terms of the means by which they are accomplished, the persons 

they appear intended to coerce or intimidate, or the locale in 

which their perpetrators operate or seek asylum.

Intrusion Detection System (IDS). The combination of 

components, including sensors, control units, transmission lines, 

and monitor units, integrated to operate in a specified manner. 

J

Jersey barrier. A protective concrete barrier initially and still 

used as a highway divider that now also functions as an expedient 

method for traffic speed control at entrance gates and to keep 

vehicles away from buildings.

L

Laminated glass. A flat lite of uniform thickness consisting of 

two monolithic glass plies bonded together with an interlayer 

material as defined in Specification C1172. Many different 

interlayer materials are used in laminated glass.

Landscaping. The use of plantings (shrubs and trees), with or 

without landforms and/or large boulders, to act as a perimeter 

barrier against defined threats.

Layers of protection. A traditional approach in security 

engineering using concentric circles extending out from an area to 

be protected as demarcation points for different security strategies. 

Level of protection (LOP). The degree to which an asset is 

protected against injury or damage from an attack. 

Liaison. An agency official sent to another agency to facilitate 

interagency communications and coordination.
B-14 GENERAL GLOSSARY 

Limited area. A restricted area within close proximity of a security 

interest. Uncontrolled movement may permit access to the item. 

Escorts and other internal restrictions may prevent access to the 

item. See controlled area and exclusion area.

Line of sight (LOS). Direct observation between two points with 

the naked eye or hand-held optics.

Line-of-sight sensor. A pair of devices used as an intrusion 

detection sensor that monitor any movement through the field 

between the sensors.

Local government. Any county, city, village, town, district, or 

political subdivision of any state, and Indian tribe or authorized 

tribal organization, or Alaska Native village or organization, 

including any rural community or unincorporated town or village 

or any other public entity.

M

Mail-bomb delivery. Bombs or incendiary devices delivered to the 

target in letters or packages.

Minimum measures. Protective measures that can be applied to 

all buildings regardless of the identified threat. These measures 

offer defense or detection opportunities for minimal cost, 

facilitate future upgrades, and may deter acts of aggression.

Mitigation. Those actions taken to reduce the exposure to and 

impact of an attack or disaster.

Motion detector. An intrusion detection sensor that changes state 

based on movement in the sensor’s field of view.

Moving vehicle bomb. An explosive-laden car or truck driven into 

or near a building and detonated.

Mutual Aid Agreement. A pre-arranged agreement developed 

between two or more entities to render assistance to the parties of 

the agreement.
GENERAL GLOSSARY B-15

N

Natural hazard. Naturally-occurring events such as floods, 

earthquakes, tornadoes, tsunami, coastal storms, landslides, and 

wildfires that strike populated areas. A natural event is a hazard 

when it has the potential to harm people or property (FEMA 

386- 2 Understanding Your Risks). The risks of natural hazards may 

be increased or decreased as a result of human activity; however, 

they are not inherently human-induced.

Natural protective barriers. Natural protective barriers are 

mountains and deserts, cliffs and ditches, water obstacles, or 

other terrain features that are difficult to traverse.

Non-exclusive zone. An area around an asset that has controlled 

entry, but shared or less restrictive access than an exclusive zone.

Non-persistent agent. An agent that, upon release, loses its 

ability to cause casualties after 10 to 15 minutes. It has a high 

evaporation rate, is lighter than air, and will disperse rapidly. 

It is considered to be a short-term hazard; however, in small, 

unventilated areas, the agent will be more persistent.

Nuclear, biological, or chemical weapons. Also called Weapons 

of Mass Destruction (WMD). Weapons that are characterized by 

their capability to produce mass casualties.

P

Passive vehicle barrier. A vehicle barrier that is permanently 

deployed and does not require response to be effective.

Perimeter barrier. A fence, wall, vehicle barrier, landform, or line 

of vegetation applied along an exterior perimeter used to obscure 

vision, hinder personnel access, or hinder or prevent vehicle access.

Persistent agent. An agent that, upon release, retains its casualty 

producing effects for an extended period of time, usually anywhere 
B-16 GENERAL GLOSSARY 

from 30 minutes to several days. A persistent agent usually has a 

low evaporation rate and its vapor is heavier thanair; therefore, 

its vapor cloud tends to hug the ground. It is considered to be a 

long-term hazard. Although inhalation hazards are still a concern, 

extreme caution should be taken to avoid skin contact as well.

Physical security. The part of security concerned with measures/

concepts designed to safeguard personnel; to prevent unauthorized 

access to equipment, installations, materiel, and documents; and to 

safeguard them against espionage, sabotage, damage, and theft.

Planter barrier. A passive vehicle barrier, usually constructed of 

concrete and filled with dirt (and flowers for aesthetics). Planters, 

along with bollards, are the usual street furniture used to keep 

vehicles away from existing buildings. Overall size and the depth 

of installation below grade determine the vehicle stopping 

capability of the individual planter.

Plume. Airborne material spreading from a particular source; the 

dispersal of particles, gases, vapors, and aerosols into the atmosphere.

Polycarbonate glazing. A plastic glazing material with enhanced 

resistance to ballistics or blast effects.

Preliminary Damage Assessment (PDA). A mechanism used to 

determine the impact and magnitude of damage and the resulting 

unmet needs of individuals, businesses, the public sector, and the 

community as a whole. Information collected is used by the state 

as a basis for the Governor’s request for a Presidential declaration, 

and by FEMA to document the recommendation made to the 

President in response to the Governor’s request. PDAs are made 

by at least one state and one federal representative. A local 

government representative familiar with the extent and location 

of damage in the community often participates; other state and 

federal agencies and voluntary relief organizations also may be 

asked to participate, as needed.

Preparedness. Establishing the plans, training, exercises, and 

resources necessary to enhance mitigation of and achieve 

readiness for response to, and recovery from all hazards, 

disasters, and emergencies, including WMD incidents.
GENERAL GLOSSARY B-17

Primary asset. An asset that is the ultimate target for compromise 

by an aggressor.

Primary gathering building. Inhabited buildings routinely 

occupied by 50 or more personnel. This designation applies to 

the entire portion of a building that meets the population density 

requirements for an inhabited building.

Probability of detection (POD). A measure of an intrusion 

detection sensor’s performance in detecting an intruder within 

its detection zone.

Probability of intercept. The probability that an act of aggression 

will be detected and that a response force will intercept the 

aggressor before the asset can be compromised.

Progressive collapse. A chain reaction failure of building 

members to an extent disproportionate to the original localized 

damage. Such damage may result in upper floors of a building 

collapsing onto lower floors.

Protective barriers. Define the physical limits of a site, activity, or 

area by restricting, channeling, or impeding access and forming a 

continuous obstacle around the object.

Protective measures. Elements of a protective system that protect 

an asset against a threat. Protective measures are divided into 

defensive and detection measures.

Protective system. An integration of all of the protective 

measures required to protect an asset against the range of threats 

applicable to the asset.

R

Radiation. High-energy particles or gamma rays that are emitted 

by an atom as the substance undergoes radioactive decay. 

Particles can be either charged alpha or beta particles or neutral 

neutron or gamma rays.
B-18 GENERAL GLOSSARY 

Radiation sickness. The symptoms characterizing the sickness 

known as radiation injury, resulting from excessive exposure of 

the whole body to ionizing radiation.

Radiological monitoring. The process of locating and measuring 

radiation by means of survey instruments that can detect and 

measure (as exposure rates) ionizing radiation.

Recovery. The long-term activities beyond the initial crisis period 

and emergency response phase of disaster operations that focus 

on returning all systems in the community to a normal status 

or to reconstitute these systems to a new condition that is less 

vulnerable.

Response. Executing the plan and resources identified to 

perform those duties and services to preserve and protect life and 

property as well as provide services to the surviving population.

Restricted area. Any area with access controls that is subject to 

these special restrictions or controls for security reasons. See 

controlled area, limited area, exclusion area, and exclusion zone.

Risk. The potential for loss of, or damage to, an asset. It is 

measured based upon the value of the asset in relation to the 

threats and vulnerabilities associated with it.

Rotating drum or rotating plate vehicle barrier. An active vehicle 

barrier used at vehicle entrances to controlled areas based on a 

drum or plate rotating into the path of the vehicle when signaled.

S

Sacrificial roof or wall. Roofs or walls that can be lost in a blast 

without damage to the primary asset.

Safe haven. Secure areas within the interior of the facility. A safe 

haven should be designed such that it requires more time to 

penetrate by aggressors than it takes for the response force to reach 

the protected area to rescue the occupants. It may be a haven from a 

physical attack or an air-isolated haven from CBR contamination.
GENERAL GLOSSARY B-19

Secondary asset. An asset that supports a primary asset and whose 

compromise would indirectly affect the operation of the primary 

asset.

Secondary hazard. A threat whose potential would be realized 

as the result of a triggering event that of itself would constitute 

an emergency (e.g., dam failure might be a secondary hazard 

associated with earthquakes).

Situational crime prevention. A crime prevention strategy based 

on reducing the opportunities for crime by increasing the effort 

required to commit a crime, increasing the risks associated 

with committing the crime, and reducing the target appeal or 

vulnerability (whether property or person). This opportunity 

reduction is achieved by management and use policies such as 

procedures and training, as well as physical approaches such as 

alteration of the built environment.

Specific threat. Known or postulated aggressor activity focused on 

targeting a particular asset.

Stand-off distance. A distance maintained between a building 

or portion thereof and the potential location for an explosive 

detonation or other threat.

Stand-off weapons. Weapons such as anti-tank weapons and 

mortars that are launched from a distance at a target.

State Coordinating Officer (SCO). The person appointed by 

the Governor to coordinate state, commonwealth, or territorial 

response and recovery activities with FRP-related activities of the 

Federal Government, in cooperation with the FCO.

State Liaison. A FEMA official assigned to a particular state, who 

handles initial coordination with the state in the early stages of an 

emergency.

Stationary vehicle bomb. An explosive-laden car or truck stopped 

or parked near a building.

Structural protective barriers. Manmade devices (e.g., fences, 

walls, floors, roofs, grills, bars, roadblocks, signs, or other 

construction) used to restrict, channel, or impede access.
B-20 GENERAL GLOSSARY 

Superstructure. The supporting elements of a building above the 

foundation.

Supplies-bomb delivery. Bombs or incendiary devices concealed 

and delivered to supply or material handling points such as 

loading docks.

T

Tactics. The specific methods of achieving the aggressor’s 

goals to injure personnel, destroy assets, or steal materiel or 

information.

Tangle-foot wire. Barbed wire or tape suspended on short 

metal or wooden pickets outside a perimeter fence to create an 

obstacle to approach.

Taut wire sensor. An intrusion detection sensor utilizing a 

column of uniformly spaced horizontal wires, securely anchored 

at each end and stretched taut. Each wire is attached to a sensor 

to indicate movement of the wire.

Technological hazards. Incidents that can arise from human 

activities such as manufacture, transportation, storage, and use 

of hazardous materials. For the sake of simplicity, it is assumed 

that technological emergencies are accidental and that their 

consequences are unintended.

Terrorism. The unlawful use of force and violence against 

persons or property to intimidate or coerce a government, the 

civilian population, or any segment thereof, in furtherance of 

political or social objectives.

Thermally tempered glass (TTG). Glass that is heat-treated to 

have a higher tensile strength and resistance to blast pressures, 

although with a greater susceptibility to airborne debris.

Threat. Any indication, circumstance, or event with the potential 

to cause loss of, or damage to an asset.
GENERAL GLOSSARY B-21

Threat analysis. A continual process of compiling and examining all 

available information concerning potential threats and human-caused 

hazards. A common method to evaluate terrorist groups is to review 

the factors of existence, capability, intentions, history, and targeting.

TNT equivalent weight. The weight of TNT (trinitrotoluene) that 

has an equivalent energetic output to that of a different weight of 

another explosive compound.

Tornado. A local atmospheric storm, generally of short duration, 

formed by winds rotating at very high speeds, usually in a 

counter-clockwise direction. The vortex, up to several hundred 

yards wide, is visible to the observer as a whirlpool-like column of 

winds rotating about a hollow cavity or funnel. Winds may reach 

300 miles per hour or higher.

Toxic-free area. An area within a facility in which the air supply is 

free of toxic chemical or biological agents.

Toxicity. A measure of the harmful effects produced by a given 

amount of a toxin on a living organism.

Triple-standard concertina (TSC) wire. This type of fence uses 

three rolls of stacked concertina. One roll will be stacked on top 

of two other rolls that run parallel to each other while resting on 

the ground, forming a pyramid.

U

Unobstructed space. Space around an inhabited building without 

obstruction large enough to conceal explosive devices 150 mm (6 

inches) or greater in height.

V

Video motion detection. Motion detection technology that looks 

for changes in the pixels of a video image.
B-22 GENERAL GLOSSARY

Visual surveillance. The aggressor uses ocular and photographic 

devices (such as binoculars and cameras with telephoto lenses) to 

monitor facility or installation operations or to see assets.

Volumetric motion sensor. An interior intrusion detection sensor 

that is designed to sense aggressor motion within a protected 

space.

Vulnerability. Any weakness in an asset or mitigation measure 

than can be exploited by an aggressor (potential threat 

element), adversary, or competitor. It refers to the organization’s 

susceptibility to injury.

W

Warning. The alerting of emergency response personnel and 

the public to the threat of extraordinary danger and the related 

effects that specific hazards may cause.

Watch. Indication in a defined area that conditions are favorable 

for the specified type of severe weather (e.g., flash flood watch, 

severe thunderstorm watch, tornado watch, tropical storm watch).

Waterborne contamination. Chemical, biological, or radiological 

agent introduced into and fouling a water supply.

Weapons of Mass Destruction (WMD). Any device, material, 

or substance used in a manner, in a quantity or type, or under 

circumstances showing an intent to cause death or serious injury 

to persons, or significant damage to property. An explosive, 

incendiary, or poison gas, bomb, grenade, rocket having a 

propellant charge of more than 4 ounces, or a missile having an 

explosive incendiary charge of more than 0.25 ounce, or mine 

or device similar to the above; poison gas; weapon involving a 

disease organism; or weapon that is designed to release radiation 

or radioactivity at a level dangerous to human life.
CHEMICAL, BIOLOLOGICAL, AND RADIOLOGICAL GLOSSARY C-1

CHEMICAL WARFARE AGENT CHARACTERISICS

Note:

Tables reduced for 

PDF purposes only. 

Tables appear as 

11x17 horizontal 

foldout pages in the 

printed publication.

CHEMICAL, BIOLOLOGICAL, AND RADIOLOGICAL GLOSSARY C-3

SELECTED BIOLOGICAL AGENT CHARACTERISICS
This appendix contains some CBR terms that do not actually 

appear in this manual. They have been included to present a comprehensive list that pertains to this series of publications.

CHEMICAL TERMS

A

Acetylcholinesterase. An enzyme that hydrolyzes the 

neurotransmitter acetylcholine. The action of this enzyme is 

inhibited by nerve agents.

Aerosol. Fine liquid or solid particles suspended in a gas (e.g., fog 

or smoke).

Atropine. A compound used as an antidote for nerve agents.

C

Casualty (toxic) agents. Produce incapacitation, serious injury, or 

death, and can be used to incapacitate or kill victims. They are the 

blister, blood, choking, and nerve agents.

Blister agents. Substances that cause blistering of the 

skin. Exposure is through liquid or vapor contact with any 

exposed tissue (eyes, skin, lungs). Examples are distilled 

mustard (HD), nitrogen mustard (HN), lewisite (L), 

mustard/lewisite (HL), and phenodichloroarsine (PD).

Blood agents. Substances that injure a person by 

interfering with cell respiration (the exchange of oxygen 

and carbon dioxide between blood and tissues). Examples 

are arsine (SA), cyanogens chloride (CK), hydrogen 

chloride (HCl), and hydrogen cyanide (AC).

Choking/lung/pulmonary agents. Substances that cause 

physical injury to the lungs. Exposure is through 

inhalation. In extreme cases, membranes swell and 
BIBLIOGRAPHY D

BIBLIOGRAPHY D-1

American Association of State Highway and 

Transportation Officials

A Guide to Highway Vulnerability Assessment for Critical Asset 

Identification and Protection, May 2002 , The American Association 

of State Highway and Transportation Officials’ Security Task Force, 

Washington, DC

http://security.transportation.org/community/security/guides.html

The American Institute of Architects

Building Security Through Design: A Primer for Architects, Design 

Professionals, and their Clients, November 2001, The American 

Institute of Architects (book)

http://www.aia.org/security

American Institute of Chemical Engineers

Pub No: G-79, Guidelines for Analyzing and Managing the Security 

Vulnerabilities at Fixed Chemical Sites, 2002, Center for Chemical 

Process Safety, ISBN No: 0-8169-0877-X

http://www.aiche.org/ccpssecurity

American Medical Association

Physical injuries and fatalities resulting from the Oklahoma City bombing, 

August 7, 1996, S. Mallonee, S. Shariat, G. Stennies, R. Waxweiler, 

D. Hogan, and F. Jordan., The Journal of the American Medical 

Association, Vol. 276 No. 5., pp 382-387 Abstract at URL:

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American Society of Civil Engineers

Architectural Engineering Institute of American Society of Civil 

Engineers, AEI Newsletter, The Team, Special Terrorism Issue, Fall 

2001, Volume 4, Issue 3

http://www.asce.org/pdf/aei_11_1.pdf
D-2 BIBLIOGRAPHY 

Blast Effects on Buildings: Design of Buildings to Optimize Resistance to Blast 

Loading, 1995, G.C. Mays and P.D. Smith, London: Thomas Telford, 

Ltd., American Society of Civil Engineers, ISBN: 0-7277-2030-9

http://www.pubs.asce.org/BOOKdisplay.cgi?9990338

Blast Resistant Design of Commercial Buildings, 1996, M. Ettouney, R. 

Smilowitz, and T. Rittenhouse, Practice Periodical on Structural 

Design and Construction, Vol. 1, No. 1, February 1996, American 

Society of Civil Engineers

http://ojps.aip.org/dbt/dbt.jsp?KEY=PPSCFX&Volume=1&Issue=1

A preprint of the final article is available at

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Design of Blast Resistant Buildings in Petrochemical Facilities, 1997, 

American Society of Civil Engineers, ISBN: 0-7844-0265-5

http://www.pubs.asce.org/BOOKdisplay.cgi?9704510

Glass-Related Injuries in Oklahoma City Bombing, Journal of 

Performance of Constructed Facilities, May 1999, 13, No. 2, H. 

Scott Norville, Natalie Harville, Edward J. Conrath, Sheryll Shariat, 

and Sue Mallonee

http://www.pubs.asce.org/WWWdisplay.cgi?9902006

Lessons from the Oklahoma City Bombing: Defensive Design Techniques,

January 1997, Eve E. Hinman and David J. Hammond, January 

1997, American Society of Civil Engineers (ASCE Press), Reston, 

VA, ISBN: 0784402175

http://www.asce.org/publications/booksdisplay.cfm?type=9702295

Minimum Design Loads for Buildings and Other Structures, ASCE 7-

02,2002, American Society of Civil Engineers, ISBN: 0-7844-0624-

3 [Note revision of 7-98, does not include building security or 

antiterrorism, but covers all natural hazards]

http://www.pubs.asce.org/ASCE7.html?9991330

Structural Engineering Institute of American Society of Civil 

Engineers, Structural Design for Physical Security: State of the Practice, 
BIBLIOGRAPHY D-3

1999, Edward Conrath, et al., Reston, VA, Structural Engineering 

Institute of American Society of Civil Engineers

http://www.pubs.asce.org/BOOKdisplay.cgi?9990571

Vulnerability and Protection of Infrastructure Systems: The State of the Art, 

An ASCE Journals Special Publication compiling articles from 2002 

and earlier available online

https://ascestore.aip.org/OA_HTML/aipCCtpItmDspRte.jsp?a=b

& item=39885

American Society of Heating, Refrigerating, and 

Air-Conditioning Engineers

Defensive Filtration, ASHRAE Journal, December 2002, James D. Miller

http://resourcecenter.ashrae.org/store/ashrae/newstore.cgi?itemid 

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Report of Presidential Ad Hoc Committee for Building Health and Safety 

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Safety and Environmental Security under Extraordinary Incidents, 

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http://xp20.ashrae.org/about/extraordinary.pdf

Risk Management Guidance for Health and Safety under Extraordinary 

Incidents, ASHRAE 2002 Winter Meeting Report, January 12, 2002

http://atfp.nfesc.navy.mil/pdf/ASHRAE%20CBR%20Guidance.pdf

or

http://engineering.tamu.edu/safety/guidelines/faclab/ASHRAE_

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Standard 62-2001, Ventilation for Acceptable Indoor Air Quality (ANSI 

Approved), ISSN 1041-2336, addenda to basic ANSI/ASHRAE 

Standard 62 basic (1989)

http://resourcecenter.ashrae.org/store/ashrae/newstore.cgi?itemid= 

6852&view=item&categoryid=311&page=1&loginid=29483
D-4 BIBLIOGRAPHY 

Building Owners and Managers Association 

International

How to Design and Manage Your Preventive Maintenance Program, 1996

http://www.boma.org/pubs/bomapmp.htm

Centers for Disease Control and Prevention/

National Institute for Occupational Safety and 

Health

Publication No. 2002-139, Guidance for Protecting Building 

Environments from Airborne Chemical, Biological, or Radiological Attacks, 

May 2002, Cincinnati, OH

http://www.cdc.gov/niosh/bldvent/2002-139.html

Publication No. 2003-136, Guidance for Filtration and Air Cleaning 

Systems to Protect Building Environments from Airborne Chemical, 

Biological, or Radiological Attacks, April 2003, Cincinnati, OH

http://www.cdc.gov/niosh/docs/2003-136/2003-136.html

Central Intelligence Agency

Chemical, Biological, Radiological Incident Handbook, October 1998

http://www.cia.gov/cia/publications/cbr_handbook/cbrbook.htm

Council on Tall Buildings and Urban Habitat

Building Safety Enhancement Guidebook, 2002

http://www.ctbuh.org

Task Force on Tall Buildings: “The Future,” October 15, 2001

http://www.lehigh.edu/ctbuh/htmlfiles/hot_links/report.pdf

or http://www.ctbuh.org/htmlfiles/hot_links/report.pdf

Federal Aviation Administration

DOT/FAA/AR-00/52, Recommended Security Guidelines for Airport 

Planning, Design and Construction, Revised June 2001, Associate 

Administrator for Civil Aviation Security Office of Civil Aviation 

Security, Policy and Planning, Federal Aviation Administration, 

Washington, DC 20591 (not available on Internet)
BIBLIOGRAPHY D-5

FAA Order 1600.69A, FAA Facility Security Management Program, 

updated FAA Order 1600.69B to be published shortly – The 

Federal Aviation Administration’s criteria for the protection of its 

facilities. [For Official Use Only] (not available on Internet)

Federal Emergency Management Agency

FEMA 152, Seismic Considerations: Apartment Buildings, Earthquake 

Hazards Reduction Series 37, November 1988, Washington, DC (not 

available on Internet) Contact FEMA Distribution Center, P.O. Box 

2012, 8231 Stayton Drive, Jessup, MD 20794-2012, Telephone:

1-800-480-2520, Fax: 301-362-5335

FEMA 153, Seismic Considerations: Office Buildings, Earthquake Hazards 

Reduction Series 38, November 1988, Washington, DC (not available 

on Internet) Contact FEMA Distribution Center, P.O. Box 2012, 

8231 Stayton Drive, Jessup, MD 20794-2012, Telephone: 1-800-480-

2520, Fax: 301-362-5335

FEMA 154, Rapid Visual Screening of Buildings for Seismic Hazards: A 

Handbook (2nd Edition), 2002, 1988, Washington, DC (not available 

on Internet) Contact FEMA Distribution Center, P.O. Box 2012, 

8231 Stayton Drive, Jessup, MD 20794-2012, Telephone: 1-800-480-

2520, Fax: 301-362-5335

FEMA 277, The Oklahoma City Bombing: Improving Building 

Performance through Multi-Hazard Mitigation, August 1, 1996, 

Washington, DC

http://www.fema.gov/mit/bpat/bpat009.htm

FEMA 372, Mitigation Resources for Success (CD-ROM), October 2001, 

Washington, DC

http://www.fema.gov/pdf/library/poster_fnl2.pdf

FEMA 386-2, Understanding Your Risks, Identifying Hazards and 

Estimating Losses, August 2001

http://www.fema.gov/fima/planning_toc3.shtm
D-6 BIBLIOGRAPHY 

FEMA 386-7, Integrating Human-Caused Hazards Into Mitigation 

Planning, September 2002

http://www.fema.gov/fima/antiterrorism/resources.shtm

FEMA 403, World Trade Center Building Performance Study: Data 

Collection, Preliminary Observations, and Recommendations, May 2002, 

Washington, DC

http://www.fema.gov/library/wtcstudy.shtm

State and Local Guide 101, Guide for All-Hazard Emergency Operations 

Planning, Chapter 6, Attachment G, Terrorism, April 2001

http://www.fema.gov/rrr/allhzpln.shtm

General Services Administration

Balancing Security and Openness: A Thematic Summary of a Symposium 

on Security and the Design of Public Buildings, November 30, 1999

http://hydra.gsa.gov/pbs/pc/gd_files/SecurityOpenness.pdf

Cost Impact of ISC Security Criteria, GSA & Applied Research Associates, 

Inc., L. Bryant and J. Smith, Vicksburg, MS [Restricted Access]

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Facility Standards for the Public Building Service (PBS-P100); Chapter 

8, Security Design, Revised November 2000

http://hydra.gsa.gov/pbs/pc/facilitiesstandards/

Mail Center Manager’s Security Guide – Second Edition, October 22, 2002

http://www.gsa.gov//attachments/GSA_PUBLICATIONS/

extpub/MailCenterManagersSecurityGuideV2.pdf

Progressive Collapse Analysis and Design Guidelines for New Federal 

Office Buildings and Major Modernization Projects, November 2000 

[Restricted Access]

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Security Reference Manual, Part 3: Blast Design and Assessment 

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http://www.oca.gsa.gov/specialphp/References.php
BIBLIOGRAPHY D-7

Healthy Building International, Inc.

Vulnerability Assessments and Counter Terrorist Protocols

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Interagency Security Committee (executive agent 

– GSA)

ISC Security Design Criteria for New Federal Office Buildings and 

Major Modernization Projects, May 28, 2001, [For Official Use Only] 

[Restricted Access]

http://www.oca.gsa.gov/specialphp/References.php

Institute of Transportation Engineers

The Influence of Traffic Calming Devices upon Fire Vehicle Travel Times,

Michael A. Coleman, 1997, ITE Annual Meeting Compendium, 

1997 pp. 838-845

http://webservices.camsys.com/fhwa/cmn/cmn33.htm

Split Speed Bump, 1998, Kathy Mulder, Washington, DC, TE 

International Conference, 1998

http://www.ite.org/traffic/documents/CCA98A33.pdf

Lawrence Berkeley National Lab

Protecting Buildings From a Biological or Chemical Attack: actions to take 

before or during a release. LBNL/PUB-51959, January 10, 2003

http://securebuildings.lbl.gov/images/bldgadvice.pdf

National Academy of Sciences

Combating Terrorism: Prioritizing Vulnerabilities and Developing 

Mitigation Strategies, Project Identification Number: NAEP-R-02-01-

A, National Academy of Engineering on-going project – results to 

be published.

http://www4.nationalacademies.org/webcr.nsf/ProjectScopeDisplay/ 

NAEP-R-02-01-A?OpenDocument
D-8 BIBLIOGRAPHY 

National Capital Planning Commission

Designing for Security in the Nation’s Capital, October 2001

http://www.ncpc.gov/planning_init/security/DesigningSec.pdf

The National Capital Planning Urban Design and Security Plan, 

October 2002

http://www.ncpc.gov/publications/udsp/Final%20UDSP.pdf

National Institute of Building Sciences

Whole Building Design Guide: Provide Security for Building Occupants 

and Assets

http://www.wbdg.org/design/index.php?cn=2.7.4&cx=0

National Research Council

Protecting Buildings and People from Terrorism: Technology Transfer for 

Blast-effects Mitigation, 2001, National Academy Press, Washington, 

DC, ISBN 0-309-08286-2

http://books.nap.edu/books/0309082862/html/index.html

Protecting Buildings From Bomb Blast, Transfer of Blast-Effects Mitigation 

Technologies from Military to Civilian Applications, 1995, National 

Academy Press, Washington, DC, ISBN 0-309-05375-7

http://books.nap.edu/books/0309053757/html/index.html

Protection of Federal Office Buildings Against Terrorism, 1988, 

Committee on the Protection of Federal Facilities Against Terrorism, 

Building Research Board, National Academy Press, Washington, 

DC, ISBN 0-309-07691-9

http://books.nap.edu/books/0309076463/html/index.html

Society of American Military Engineers

National Symposium of Comprehensive Force Protection, October 

2001, Charleston, SC, Lindbergh & Associates. For a list of 

participants, access

http://www.same.org/forceprot/force.htm
BIBLIOGRAPHY D-9

Technical Support Working Group (TSWG)

Terrorist Bomb Threat Stand-Off Card with Explanation of Use

http://www.tswg.gov/tswg/prods_pubs/newBTSCPress.htm

The House National Security Committee

Statement of Chairman Floyd D. Spence on the Report of the 

Bombing of Khobar Towers, August 1996, Washington, DC

http://www.house.gov/hasc/Publications/104thCongress/

Reports/saudi.pdf

U.S. Air Force

ESL-TR-87-57, Protective Construction Design Manual, November 

1989; Contact Airbase Technologies Division (AFRL/MLQ) at 

Tyndall Air Force Base, FL, via e-mail to techinfo@afrl.af.mil. 

[Superceded by Army Technical Manual TM 5-855-1 (Air Force

Pamphlet AFPAM 32-1147(I), Navy Manual NAVFAC P-1080, 

DSWA Manual DAHSCWEMAN-97), December 1997] 

Expedient Hardening Methods for Structures Subjected to the Effect of 

Nonnuclear Munitions, October 1990, Wright Laboratory Report 

(not available on Internet)

Installation Entry Control Facilities Design Guide, October 2002, Air 

Force Center for Environmental Excellence

http://www.afcee.brooks.af.mil/dc/dcd/gate/index.html

Installation Force Protection Guide, 1997, Air Force Center for 

Environmental Excellence

http://www.afcee.brooks.af.mil/dc/dcd/arch/force.pdf

Vehicle Bomb Mitigation Guide, July 1, 1999, Force Protection 

Battlelab [For Official Use Only] Contact the USAF Force Protection 

Battlelab, Lackland Air Force Base, TX, Telephone: (210)671-0058
D-10 BIBLIOGRAPHY 

U.S. Army

Field Manuals (FM)

FM 3-19.30, Physical Security, January 8, 2001, Washington, DC

http://www.adtdl.army.mil/cgi-bin/atdl.dll/fm/3-19.30/fm3-19.30.pdf

or

http://www.wood.army.mil/mpdoctrine/PDF_Files/FM_3-19.30.pdf

FM 5-114, Engineer Operations Short of War, July 13, 1992

http://155.217.58.58/cgi-bin/atdl.dll/fm/5-114/toc.htm

Technical Instruction 853-01 (Draft), Protecting Buildings and Their 

Occupants from Airborne Hazards, October 2001

http://buildingprotection.sbccom.army.mil/basic/airborne_hazards

U.S. Army Corps of Engineers

Engineer Technical Letters (ETL)

ETL 1110-3-494, Airblast Protection Retrofit for Unreinforced Concrete 

Masonry Walls, July 14, 1999 [Restricted Access]

http://www.usace.army.mil/inet/usace-docs/eng-tech-ltrs

ETL 1110-3-495, Estimating Damage to Structures from Terrorist Bombs 

Field Operations Guide, July 14, 1999 [Restricted Access]

http://www.usace.army.mil/inet/usace-docs/eng-tech-ltrs

ETL 1110-3-498, Design of Collective Protection Shelters to Resist 

Chemical, Biological, and Radiological (CBR) Agents, February 24, 1999

http://www.usace.army.mil/inet/usace-docs/eng-tech-ltrs

ETL 1110-3-501, Window Retrofit Using Fragment Retention Film with 

Catcher Bar System, July 14, 1999 [Restricted Access]

http://www.usace.army.mil/inet/usace-docs/eng-tech-ltrs
BIBLIOGRAPHY D-11

Protective Design – Mandatory Center of Expertise – Technical 

Reports

PDC-TR-91-6, Blast Analysis Manual, Part 1 – Level of Protection 

Assessment Guide, July 1991 [For Official Use Only] Contact U.S. Army 

Corps of Engineers Protective Design Center, ATTN: CENWOED-ST, 215 N. 17th Street, Omaha, NE 68102-4978, Telephone: 

(402)221-4918

Technical Manuals (TM)

TM 5-853-1, Security Engineering Project Development, May 12, 1994, 

also Air Force Manual 32-1071, Volume 1 [For Official Use Only]

http://www.usace.army.mil/inet/usace-docs/armytm

TM 5-853-2, Security Engineering Concept Design, May 12, 1994, also 

Air Force Manual 32-1071, Volume 2 [For Official Use Only]

http://www.usace.army.mil/inet/usace-docs/armytm

TM 5-853-3, Security Engineering Final Design, May 12, 1994, also Air 

Force Manual 32-1071, Volume 3 [For Official Use Only]

http://www.usace.army.mil/inet/usace-docs/armytm

TM 5-853-4, Security Engineering Electronic Security Systems, May 12, 1994

http://www.usace.army.mil/inet/usace-docs/armytm

TM 5-855-4, Heating, Ventilation, and Air Conditioning of 

Hardened Installations, November 28, 1986

http://www.usace.army.mil/inet/usace-docs/armytm/tm5-855-4/

toc.htm

TM 5-1300, Structures to Resist Accidental Explosions, November 

19, 1990, (also Navy NAVFAC (Naval Facilities) P-397, Air Force 

Regulation 88-2); Contact David Hyde, U.S. Army Engineer 

Research and Development Center, 3909 Halls Ferry Road, 

Vicksburg, MS 39180 or via e-mail to hyded@ex1.wes.army.mil
D-12 BIBLIOGRAPHY 

U.S. Department of Commerce

Administrative Orders (DAO)

DAO 206-5, Occasional Use of Public Areas in Public Buildings, 

December 9, 1986

http://www.osec.doc.gov/bmi/daos/206-5.htm

DAO 207-1, Security Programs, June 24, 1991, Amended September 

6, 1991

http://www.osec.doc.gov/bmi/daos/207-1.htm

Critical Infrastructure Assurance Office

Vulnerability Assessment Framework 1.1, October 1998

http://www.ciao.gov/resource/vulassessframework.pdf

Practices For Securing Critical Information Assets, January 2000

http://www.ciao.gov/resource/Practices_For_Securing_Critical_

Information_Assets.pdf

U.S. Department of Defense

DoD Security Engineering Manual [Expected to have a major portion 

for public distribution once published as Unified Facilities Criteria 

and a smaller portion For Official Use Only similar to the UFC 

for AT Standards for Buildings listed below. This publication will 

replace Army Technical Manual 5-853 (Air Force Joint Manual 32-

1071), Volumes 1, 2, and 3 and Navy Military Handbook 1013/1A] 

DoD O-2000.12-H, Protection of DoD Personnel and Activities Against 

Acts of Terrorism and Political Turbulence: Mandatory Standards and 

Implementing Guidance, with Changes 1 and 2, February 1993, Change 1 

— May 21, 1993, Change 2 – October 3, 1997 [For Official Use Only]

http://www.dtic.mil/whs/directives/corres/pub1.html

Force Protection Equipment Demonstration IV, 6-8 May 2003

http://www.fped4.org

Interim Antiterrorism/Force Protection Construction Standards, December 

16, 1999 [For Official Use Only] Contact U.S. Army Engineer 
BIBLIOGRAPHY D-13

District, ATTN: CENWO-ED-ST, 215 North 17th Street, Omaha, 

NE 68102-4978, Telephone: (402)221-4918.

Interim Antiterrorism/Force Protection Construction Standards 

– Progressive Collapse Guidance, April 4, 2000 (not available on 

Internet) Contact U.S. Army Corps of Engineers Protective Design 

Center, ATTN: CENWO-ED-ST, 215 N. 17th Street, Omaha, NE 

68102-4978, Telephone: (402)221-4918

Unified Facilities Criteria (UFC)

UFC 3-340-01, Design and Analysis of Hardened Structures to 

Conventional Weapons Effects, June 30, 2002 [For Official Use Only] 

[Formerly Army TM 5-855-1]

http://www.hnd.usace.army.mil/techinfo/ufc/UFC3-340-01 WEB.PDF

UFC 4-010-01, DoD Minimum Antiterrorism Standards for Buildings, 

July 31, 2002

http://www.wbdg.org/ccbref/ccbdoc.php?category=ufc&docid=10

6&ref=1

Unified Facilities Guide Specifications (UFGS)

UFGS-02821A, Fencing, February 2002

http://www.ccb.org/ufgs/pdf/02821A.pdf

UFGS-02840A, Active Vehicle Barriers, February 2002

http://www.ccb.org/ufgs/pdf/02840A.pdf

UFGS-02841N, Traffic Barriers, August 2001

http://www.ccb.org/ufgs/pdf/02841N.pdf

UFGS-08390A, Blast Resistant Doors, April 2001

http://www.ccb.org/ufgs/pdf/08390.pdf

UFGS-08581, Blast Resistant Tempered Glass Windows, August 2001

http://www.ccb.org/ufgs/pdf/08581.pdf
D-14 BIBLIOGRAPHY 

UFGS-08840A, Plastic Glazing, July 1995

https://www.ccb.org/ufgs/pdf/08840A.pdf

UFGS-08850, Fragment Retention Film for Glass, July 1992

https://www.ccb.org/ufgs/pdf/08850.pdf

UFGS-11020, Security Vault Door, August 2002

http://www.ccb.org/ufgs/pdf/11020.pdf

UFGS-11025, Forced Entry Resistant Components, August 2001

http://www.ccb.org/ufgs/pdf/11025.pdf

UFGS-11035, Bullet-Resistant Components, April 2000

http://www.ccb.org/ufgs/pdf/11035.pdf

UFGS-13095A, Electromagnetic (EM) Shielding, July 2001

http://www.ccb.org/ufgs/pdf/13095A.pdf

UFGS-13420A, Self-Acting Blast Valves, November 1997

http://www.ccb.org/ufgs/pdf/13420A.pdf

U.S. Department of Education

Practical Information on Crisis Planning: A Guide for Schools and 

Communities, May 2003

http://www.ed.gov/emergencyplan

U.S. Department of Energy

DOE/TIC 11268, A Manual for the Prediction of Blast and Fragment 

Loadings on Structures, February 1992, Albuquerque, NM, Southwest 

Research Institute [not available on Internet]

U.S. Department of Homeland Security

National Strategy for Homeland Security, July 2002

http://www.dhs.gov/interweb/assetlibrary/nat_strat_hls.pdf
BIBLIOGRAPHY D-15

The National Strategy for the Physical Protection of Critical Infrastructures 

and Key Assets, February 2003

http://www.dhs.gov/interweb/assetlibrary/Physical_Strategy.pdf

National Strategy to Secure Cyberspace, February 2003

http://www.dhs.gov/interweb/assetlibrary/National_Cyberspace_

Strategy.pdf

President’s Homeland Security Advisory Council - Statewide Template 

Initiative, March 2003

http://www.dhs.gov/interweb/assetlibrary/Statewide_Template_

Initiative.pdf

State and Local Actions for Homeland Security, July 2002

http://www.whitehouse.gov/homeland/stateandlocal/State_and_

Local_Actions_for_Homeland_Security.pdf

U.S. Department of Housing and Urban 

Development

The Avoidance of Progressive Collapse, Regulatory approaches to the problem, 

PB-248 781, October 1975, Division of Energy, Building Technology 

and Standards, Office of Policy Development and Research, 

Washington, DC 20410 (not available on Internet) Creating Defensible 

Space, April 1996, Oscar Newman, Washington, DC

http://www.huduser.org

U.S. Department of Justice

Federal Bureau of Investigation (FBI)

Terrorism in the United States, 1999, Washington, DC 

Counterterrorism Division

http://www.fbi.gov/publications.htm

Office of Domestic Preparedness (ODP)

Fiscal Year 1999 State Domestic Preparedness Equipment Program, 

Assessment and Strategy Development Tool Kit, NCJ181200, May 15, 

2000, [For Official Use Only]

http://www.ojp.usdoj.gov/odp/docs/assessment.txt
D-16 BIBLIOGRAPHY 

National Institute of Justice (NIJ)

The Appropriate and Effective Use of Security Technologies in U.S. Schools: 

A Guide for Schools and Law Enforcement Agencies, September 1999, 

with U.S. Department of Education, Safe and Drug-Free Schools 

Program; and U.S. Department of Energy, Sandia National 

Laboratories

http://www.ncjrs.org/school/home.html

NIJ Guide 100-00, Guide for the Selection of Chemical Agent and Toxic 

Industrial Material Detection Equipment for Emergency First Responders, 

June 2000

http://www.ncjrs.org/pdffiles1/nij/184449.pdf

NIJ Guide 101-00, An Introduction to Biological Agent Detection 

Equipment for Emergency First Responders, December 2001

http://www.ncjrs.org/pdffiles1/nij/190747.pdf

NIJ Guide 102-00, Guide for the Selection of Personal Protective Equipment 

for Emergency First Responders, Volumes I-IV, November 2002

http://www.ncjrs.org/pdffiles1/nij/191518.pdf

NIJ Guide 602-00, Guide to the Technologies of Concealed Weapon and 

Contraband Imaging and Detection, February 2001

http://www.ncjrs.org/pdffiles1/nij/184432.pdf

NIJ Standard 0108.01, Blast Resistant Protective Materials, September 

1985 [Subscription Required]

http://www.ccb.org

Crime Prevention Through Environmental Design and Community 

Policing, August 1996, Dan Fleissner and Fred Heinzelmann, 

Washington, DC

http://www.ncjrs.org/pdffiles/crimepre.pdf

Crime Prevention Through Environmental Design in Parking Facilities, 

April 1996, Mary S. Smith, Washington, DC

http://www.ncjrs.org/pdffiles/cptedpkg.pdf
BIBLIOGRAPHY D-17

“Designing Out” Gang Homicides and Street Assaults, November 1998, 

James Lasley, Washington, DC 

http://www.ncjrs.org/pdffiles/173398.pdf

The Expanding Role of Crime Prevention Through Environmental Design 

in Premises Liability, April 1996, Corey L. Gordon and William Brill, 

Washington, DC

http://www.ncjrs.org/pdffiles/cptedlia.pdf

Physical Environment and Crime, January 1996, Ralph B. Taylor and 

Adele V. Harrell, Washington, DC

http://www.ncjrs.org/pdffiles/physenv.pdf

Visibility and Vigilance: Metro’s Situational Approach to Preventing 

Subway Crime, November 1997, Nancy G. La Vigne, Washington, DC

http://www.ncjrs.org/pdffiles/166372.pdf

U.S. Marshals Service

Vulnerability Assessment of Federal Facilities, June 28, 1995 [Restricted 

Access]

http://www.oca.gsa.gov

U.S. Department of State, Bureau of Diplomatic 

Security

Architectural Engineering Design Guidelines (5 Volumes), March 1998 

[For Official Use Only] (not available on Internet)

Certification Standard SD-STD-01.01, Revision G (Amended), 

Forced Entry and Ballistic Resistance of Structural Systems, Amended 

April 30, 1993 [Subscription Required]

http://www.ccb.org

Patterns of Global Terrorism, 2002, April 2002, Washington, DC 

http://www.state.gov/s/ct/rls/pgtrpt/2002/pdf/

Physical Security Standards Handbook, January 7, 1998 [For Official Use 

Only] (not available on Internet)
D-18 BIBLIOGRAPHY 

Structural Engineering Guidelines for New Embassy Office Buildings, 

August 1995 [For Official Use Only] (not available on Internet)

The Report of the Accountability Review Board on the Embassy Bombings 

in Nairobi and Dar es Salaam on August 7, 1998, January 1999, 

Washington, DC

http://www.state.gov/www/regions/africa/accountability_

report.html

U.S. Department of the Treasury/Bureau of 

Alcohol, Tobacco, and Firearms

Vehicle Bomb Explosion Hazard And Evacuation Distance Tables, 1999, 

request in writing, address information available at

http://www.atf.treas.gov/pub/fire-explo_pub/i54001.htm

U.S. Department of Veterans Affairs

Physical Security Assessment of Veterans Affairs Facilities, 

Recommendations of the National Institute of Building Sciences Task 

Group to the Department of Veterans Affairs, 6 September 2002

http://www.va.gov/facmgt/standard/etc/vaphysicalsecurityreport.pdf

U.S. Fire Administration (USFA of FEMA)

The Critical Infrastructure Protection Process Job Aid, May 1, 2002

http://www.usfa.fema.gov/dhtml/fire-service/cipc-jobaid.cfm

U.S. Navy

Design Manuals (DM) NAVFAC (Naval Facilities Command)

NAVFAC DM 2.08, Blast Resistant Structures, December 1986

http://www.wbdg.org/ccbref/ccbdoc.php?category=nav&docid=4

6&ref=1

NAVFAC DM 13.02, Commercial Intrusion Detection Systems (IDS), 

September 1986

http://www.wbdg.org/ccbref/ccbdoc.php?category=nav&docid=4

7&ref=1
BIBLIOGRAPHY D-19

Interim Technical Guidance (ITG) 03-03, Entry Control Facilities, 20 

February 2003

http://www.lantdiv.navfac.navy.mil/servlet page?pageid=8609,8611 

&_dad= lantdiv&_schema=LANTDIV&11435_ACTIVE_1777132.p_ 

subid= 60007&11435_ACTIVE_1777132.p_sub_siteid=51 &11435_ 

ACTIVE_1777132.p_edit=0

Military Handbooks (MIL-HDBK)

MIL-HDBK-1002/1, Structural Engineering General Requirements, 

November 30, 1987

http://www.wbdg.org/ccbref/ccbdoc.php?category=nav&docid=4

8&ref=1

MIL-HDBK-1004/4, Electrical Utilization Systems, October 13, 1987

http://www.wbdg.org/ccbref/ccbdoc.php?category=nav&docid=4

9&ref=1

MIL-HDBK-1012/3, Telecommunications Premises Distribution 

Planning, Design, and Estimating, May 31, 1996

http://www.wbdg.org/ccbref/ccbdoc.php?category=nav&docid=5

0&ref=1

MIL-HDBK-1013/1A, Design Guidelines for Physical Security of Fixed 

Land-Based Facilities, December 15, 1993. For copies, contact 

Defense Printing Service, Building 40, 700 Robbins Avenue, 

Philadelphia, PA 19111-5094, Telephone: (215)697-2179, Fax: 

(215)697-1462 or available on the National Institute of Building 

Sciences’ Construction Criteria Base

MIL-HDBK-1013/10, Design Guidelines for Security Fencing, Gates, 

Barriers, and Guard Facilities, May 14, 1993. For copies, contact 

Defense Printing Service, Building 40, 700 Robbins Avenue, 

Philadelphia, PA 19111-5094, Telephone: (215)697-2179, Fax: 

(215) 697-1462 or available on the National Institute of Building 

Sciences’ Construction Criteria Base
D-20 BIBLIOGRAPHY 

MIL-HDBK-1013/12, Evaluation of Security Glazing for Ballistic, 

Bomb, and Forced Entry Tactics, March 10, 1997. For copies, contact 

Defense Printing Service, Building 40, 700 Robbins Avenue, 

Philadelphia, PA 19111-5094, Telephone: (215)697-2179, Fax: 

(215) 697-1462 or available on the National Institute of Building 

Sciences’ Construction Criteria Base

MIL-HDBK-1013/14, Selection and Application of Vehicle Barriers, 

February 1, 1999. For copies, contact Defense Printing Service, 

Building 40, 700 Robbins Avenue, Philadelphia, PA 19111-5094, 

Telephone: (215)697-2179, Fax: (215)697-1462 or available on the 

National Institute of Building Sciences’ Construction Criteria Base

TechData Sheets – Naval Facilities Engineering Service Center 

(NFESC)

TDS-2062-SHR, Estimating Damage to Structures from Terrorist Bombs, 

September 1998 [For Official Use Only] Requests for publication can 

be made to Naval Facilities Engineering Service Center, Security 

Engineering Division (ESC66), 1100 23rd Ave, Port Hueneme, CA 

93043-4370, Telephone (805)982-1582 (Primary), (805)982-4817 

(Alternate); Fax: (805)982-1253

TDS-2063-SHR, Blast Shielding Walls, September 1998 [For 

Official Use Only] Requests for publication can be made to Naval 

Facilities Engineering Service Center, Security Engineering 

Division (ESC66), 1100 23rd Ave., Port Hueneme, CA 93043-4370, 

Telephone: (805)982-1582 (Primary), (805)982-4817 (Alternate); 

Fax: (805)982-1253

TDS-2079-SHR, Planning and Design Considerations for Incorporating 

Blast Mitigation in Mailrooms, May 2000. For copies, contact Defense 

Printing Service, Building 40, 700 Robbins Avenue, Philadelphia, 

PA 19111-5094, Telephone: (215)697-2179, Fax: (215) 697-1462
BIBLIOGRAPHY D-21

TDS-2090-SHR, Design Parameters for a Controlled Entry Point. For 

copies, contact Defense Printing Service, Building 40, 700 Robbins 

Avenue, Philadelphia, PA 19111-5094,

Telephone: (215)697-2179, Fax: (215)697-1462

User Guides — Naval Facilities Engineering Service Center 

(NFESC)

UG-2030-SHR, Security Glazing Applications, May 1998, distributed 

June 25, 1998. [For Official Use Only] Requests for publication can 

be made to Naval Facilities Engineering Service Center, Security 

Engineering Division (ESC66), 1100 23rd Ave., Port Hueneme, CA 

93043-4370, Telephone: (805)982-1582 (Primary), (805) 982-4817 

(Alternate); Fax: (805)982-1253

UG-2031-SHR, Protection Against Terrorist Vehicle Bombs, May 1998, 

distributed June 25, 1998. [For Official Use Only] Requests for 

publication can be made to Naval Facilities Engineering Service 

Center, Security Engineering Division (ESC66), 1100 23rd Ave, 

Port Hueneme, CA 93043-4370, Telephone: (805)982-15.82 

(Primary), (805) 982-4817 (Alternate); Fax: (805)982-1253

Other Books, Magazines, Magazine Articles, and 

Newspaper Articles

Archibald, Rae W., et al., 2002, Security and Safety in Los Angeles HighRise Buildings after 9/11. RAND, Santa Monica, CA, ISBN: 0-8330-

3184-8

http://www.rand.org/publications/DB/DB381

Atlas, Randall I., June 1998, Designing for Crime and Terrorism, Security 

and Technology Design, Security Technology and Design Magazine 

Reprint Services, Jim Benesh, Telephone: (800)547-7377 x324, Fax: 

(920)568-2244, e-mail: jim.benesh@cygnuspub.com

Bartlett, Sarah and Petrarca, John, The Schools of Ground Zero: Early 

Lessons Learned in Children’s Environmental Health, American Public 

Health Association, September 2002, ISBN: 0875530281 
D-22 BIBLIOGRAPHY 

Broder, James F., December 15, 1999, Risk Analysis and the Security 

Survey, 2nd Edition, Butterworth-Heinemann, Stoneham, MA, ISBN: 

0750670894

Craighead, Geoff, December 2002, High-Rise Security and Fire Life 

Safety, 2nd Edition, Academic Press, ISBN: 0750674555

Crowe, Timothy D., 2000, Crime Prevention Through Environmental 

Design: Applications Of Architectural Design And Space Management 

Concepts (2nd Edition), Stoneham, MA, Butterworth-Heinemann, 

ISBN: 075067198X

Fehr, Stephen C., July 1996, Parking Under Siege in D.C.: U.S. 

Anti-Terrorism Plan Threatens 360 Spaces, TheWashington Post, July 

13, 1996

http://www.washingtonpost.com/wp-adv/archives/advanced.htm

Fenelly, Lawrence J, June 1997, Effective Physical Security, 2nd Edition, 

Stoneham, MA, Butterworth-Heinemann, ISBN: 0-75-069873-X

Garcia, Mary Lynn, February 23, 2001, The Design and Evaluation of 

Physical Protection Systems, Stoneham, MA, Butterworth-Heinemann, 

ISBN: 0750673672

Gonchar, Joann, March 2002, Building for a Secure Future: 

Government Facilities under way incorporate already tough 

standards, Engineering News-Record, March 25, 2002

http://www.construction.com/NewsCenter/Headlines/ENR/

20020325e.asp

Greene, R.W., October 2002, Confronting Catastrophe: A GIS 

Handbook, ESRI Press, ISBN: 1589480406
BIBLIOGRAPHY D-23

Hart, Sara, March 2002, In the aftermath of September 11, the 

urban landscape appears vulnerable and random: Architects and 

consultants focus on risk assessment and security through design, 

Architectural Record, March 2002

http://archrecord.construction.com/CONTEDUC/ARTICLES/

03_02_1.asp

Kowalski, Wladyslaw Jan, P.E., Ph.D., September 26, 2002, Immune 

Building Systems Technology, McGraw-Hill Professional, ISBN: 0-07-

140246-2

Nadel, Barbara A, March 1998, Designing for Security, Architectural 

Record, March 1998

http://www.archrecord.com/CONTEDUC/ARTICLES/3_98_1.asp

Owen, David D. and R.S. Means Engineering Staff, Building Security: 

Strategies and Costs, Construction Publishers & Consultants, ISBN: 

0-87629-698-3, 2003

Pearson, Robert, September 1997, Security through Environmental 

Design, Security and Technology Design, Security Technology 

and Design Magazine Reprint Services, Jim Benesh, 

Telephone: (800) 547-7377 x324; Fax: (920) 568-2244; e-mail:

jim.benesh@cygnuspub.com

Rochon, Donald M., June 1998, Architectural Design for Security, 

Security and Technology Design, Security Technology and Design 

Magazine Reprint Services, Jim Benesh, Telephone: (800)547-7377 

x324; Fax: (920)568-2244; e-mail: jim.benesh@cygnuspub.com

Security Magazine [on-line magazine]

http://www.securitymagazine.com

Security Solutions Online: Access Control and Security Systems

[on-line magazine] http://securitysolutions.com/

Security Technology and Design [on-line and print magazine]

http://www.st-and-d.com
D-24 BIBLIOGRAPHY

Sidell, Frederick R., et al, 1998, Jane’s Chem-Bio Handbook, Jane’s 

Information Group, Alexandria, VA, ISBN 0-7106 2568-5

http://www.janes.com/company/catalog/chem_bio_hand.shtml

Smith, Keith, November 2000, Environmental Hazards: Assessing Risk 

and Reducing Disaster, Routledge, New York, NY, ISBN 0415224632

http://www.routledge-ny.com/books.cfm?isbn=0415224632
ASSOCIATIONS AND ORGANIZATIONS E

ASSOCIATIONS AND ORGANIZATIONS E-1

❍ American Lifelines Alliance 

http://www.americanlifelinesalliance.org

❍ Applied Technology Council 

http://www.atcouncil.org

❍ Battelle Memorial Institute, National Security Program 

http://www.battelle.org/natsecurity/default.stm

❍ Center for Strategic and International Studies (CSIS) 

http://www.csis.org

❍ Centers for Disease Control and Prevention (CDC)/National 

Institute for Occupational Safety and Health (NIOSH) 

http://www.cdc.gov/niosh

❍ Central Intelligence Agency (CIA) 

http://www.cia.gov

❍ Council on Tall Buildings and Urban Habitat (CTBUH) 

http://www.ctbuh.org

❍ Federal Aviation Administration (FAA) 

http://www.faa.gov

❍ Healthy Buildings International, Inc.

http://www.healthybuildings.com

❍ Institute of Transportation Engineers 

http://www.ite.org

❍ Interagency Security Committee (ISC) led by the U.S.

General Services Administration [Restricted Access] 

http://www.oca.gsa.gov

❍ International CPTED [Crime Prevention Through 

Environmental Design] Association (ICA) 

http://new.cpted.net/home.amt

❍ Lawrence Berkeley National Laboratory (LBNL) 

http://securebuildings.lbl.gov
E-2 ASSOCIATIONS AND ORGANIZATIONS 

❍ National Academy of Sciences 

http://www4.nationalacademies.org/nas/nashome.nsf

• Federal Facilities Council (FFC) Standing Committee on 

Physical Security and Hazard Mitigation 

http://www7.nationalacademies.org/ffc/Physical_

Security_ Hazard_Mitigation.html

• National Research Council 

http://www.nationalacademies.org/nrc

❍ National Defense Industrial Association (NDIA) 

http://www.ndia.org

❍ Public Entity Risk Institute 

http://www.riskinstitute.org

❍ Security Design Coalition 

http://www.designingforsecurity.org

❍ Security Industry Association (SIA) 

http://www.siaonline.org/

❍ Technical Support Working Group (Departments of Defense 

and State) 

http://www.tswg.gov

❍ U.S. Air Force Electronic System Center (ESC), Hanscom Air 

Force Base 

http://eschq.hanscom.af.mil/

❍ U.S. Army Soldiers and Biological Chemical Command 

(SBCCOM): Basic Information on Building Protection 

http://buildingprotection.sbccom.army.mil

❍ U.S. Department of Justice 

http://www.usdoj.gov

• Federal Bureau of Investigation: Terrorism in the United 

States reports 

http://www.fbi.gov/publications/terror/terroris.htm

• National Institute of Justice (NIJ) 

http://www.ojp.usdoj.gov/nij
ASSOCIATIONS AND ORGANIZATIONS E-3

• Office of Domestic Preparedness (ODP) 

http://www.ojp.usdoj.gov/odp

• U.S. Marshals Service (USMS) 

http://www.usdoj.gov/marshals

The Infrastructure Security Partnership (TISP) 

http://www.tisp.org

Founding Organizations

❍ American Council of Engineering Companies (ACEC) 

http://www.acec.org

❍ American Society of Civil Engineers (ASCE) 

http://www.asce.org

• Architectural Engineering Institute (AEI) of ASCE 

http://www.asce.org/instfound/aei.cfm

• Civil Engineering Research Foundation (CERF) of ASCE 

http://www.cerf.org

• Structural Engineering Institute (SEI) of ASCE 

http://www.seinstitute.org

❍ Associated General Contractors of America 

http://www.agc.org

❍ Construction Industry Institute 

http://construction-institute.org

❍ Federal Emergency Management Agency (FEMA) 

http://www.fema.gov

• Building Performance Assessment Team 

http://www.fema.gov/mit/bpat

• Human Caused Hazards 

http://www.fema.gov/hazards

• Mitigation Planning 

http://www.fema.gov/fima/planning.shtm
E-4 ASSOCIATIONS AND ORGANIZATIONS 

❍ Federal Facilities Council – See National Academy of Sciences

❍ National Institute of Standards and Technology (NIST), 

Building and Fire Research Laboratory 

http://www.bfrl.nist.gov

❍ Naval Facilities Engineering Command 

http://www.navfac.navy.mil

• Naval Facilities Engineering Service Center (NFESC), 

Security Engineering Center of Expertise ESC66 

http://atfp.nfesc.navy.mil

❍ Society of American Military Engineers (SAME) 

http://www.same.org

❍ The American Institute of Architects (AIA), Security Resource 

Center 

http://www.aia.org/security

❍ U.S.Army Corps of Engineers 

http://www.usace.army.mil

• Blast Mitigation Action Group, U.S. Army Corps of 

Engineers Center of Expertise for Protective Design 

http://bmag.nwo.usace.army.mil

• U.S. Army Corps of Engineers, Electronic Security Center 

http://www.hnd.usace.army.mil/esc

• U.S. Army Corps of Engineers, Protective Design Center 

http://pdc.nwo.usace.army.mil

Selected Member Organizations

❍ Air-Conditioning and Refrigeration Institute, Inc.

http://www.ari.org

❍ Air Conditioning Contractors of America 

http://www.acca.org

❍ Airport Consultants Council 

http://www.acconline.org
ASSOCIATIONS AND ORGANIZATIONS E-5

❍ Alliance for Fire & Smoke Containment & Control 

http://www.afscconline.org

❍ American Association of State Highway and Transportation 

Officials (AASHTO) 

http://www.transportation.org

❍ American Institute of Chemical Engineers, Center for 

Chemical Process Safety 

http://www.aiche.org/ccps

❍ American Planning Association 

http://www.planning.org

❍ American Portland Cement Alliance 

http://www.portcement.org/apca

❍ American Public Works Association 

http://www.apwa.net

❍ American Railway Engineering & Maintenance of Way 

Association 

http://www.arema.org

❍ American Society for Industrial Security International (ASIS) 

http://www.asisonline.org

❍ American Society of Heating, Refrigerating, and AirConditioning Engineers (ASHRAE) 

http://www.ashrae.org

❍ American Society of Interior Designers 

http://www.asid.org

❍ American Society of Landscape Architects (ASLA) 

http://www.asla.org

❍ American Society of Mechanical Engineers (ASME) 

http://www.asme.org

❍ American Underground Construction Association (AUA) 

http://www.auca.org or http://www.auaonline.org

❍ American Water Resources Association (AWRA) 

http://www.awra.org
E-6 ASSOCIATIONS AND ORGANIZATIONS 

❍ Associated Locksmiths of America 

http://www.aloa.org

❍ Association of Metropolitan Water Agencies 

http://www.amwa.net

❍ Association of State Dam Safety Officials 

http://www.damsafety.org

❍ Building Futures Council 

http://www.thebfc.com

❍ Building Owners and Managers Association International 

(BOMA), Emergency Resource Center 

http://www.boma.org/emergency

❍ California Department of Health Services, Division of 

Drinking Water & Environmental Management 

http://www.dhs.cahwnet.gov/ps/ddwem

❍ Construction Industry Roundtable 

http://www.cirt.org

❍ Construction Innovation Forum 

http://www.cif.org

❍ Construction Specifications Institute 

http://www.csinet.org

❍ Construction Users Roundtable 

http://www.curt.org

❍ Defense Threat Reduction Agency (DTRA) 

http://www.dtra.mil

❍ Design-Build Institute of America 

http://www.dbia.org

❍ Drexel (University) Intelligent Infrastructure & Transportation 

Safety Institute 

http://www.di3.drexel.edu

❍ Federal Highway Administration 

http://www.fhwa.dot.gov
ASSOCIATIONS AND ORGANIZATIONS E-7

❍ Florida Department of Transportation, Emergency 

Management Office 

http://www11.myflorida.com/safety/Emp/emp.htm

or

Florida Department of Community Affairs, Division of 

Emergency Management 

http://www.floridadisaster.org/bpr/EMTOOLS/Severe/

terrorism.htm

or 

http://www.dca.state.fl.us/bpr/EMTOOLS/CIP/critical_

infrastructure_protecti.htm

❍ George Washington University, Institute for Crisis, Disaster, 

and Risk Management 

http://www.cee.seas.gwu.edu

or 

http://www.seas.gwu.edu/~icdm

❍ Homeland Protection Institute, Ltd.

http://www.hpi-tech.org

❍ Inland Rivers Ports and Terminals 

http://www.irpt.net

❍ Institute of Electrical and Electronics Engineers, Inc. - USA 

http://www.ieeeusa.org or http://www.ieee.org/portal/

index.jsp

❍ International Association of Foundation Drilling 

http://www.adsc-iafd.com

❍ International Code Council (ICC) 

http://www.intlcode.org 

Consolidates services, products, and operations of BOCA 

(Building Officials and Code Administrators), ICBO 

(International Conference of Building Officials) and SBCCI 

Southern Building Code Congress International) into one 

member service organization — the International Code 

Council (ICC) in January 2003.

❍ International Facility Management Association (IFMA) 

http://www.ifma.org
E-8 ASSOCIATIONS AND ORGANIZATIONS 

❍ Market Development Alliance of the FRP Composites Industry 

http://www.mdacomposites.org

❍ Multidisciplinary Center for Earthquake Engineering Research 

http://mceer.buffalo.edu

❍ National Aeronautics and Space Administration 

http://www.nasa.gov

❍ National Capital Planning Commission (NCPC) 

http://www.ncpc.gov

• Security and Urban Design 

http://www.ncpc.gov/planning_init/security.html

❍ National Center for Manufacturing Sciences 

http://www.ncms.org

❍ National Concrete Masonry Association 

http://www.ncma.org

❍ National Conference of States on Building Codes and 

Standards 

http://www.ncsbcs.org

❍ National Council of Structural Engineers Associations (NCSEA) 

http://www.ncsea.com or http://dwp.bigplanet.com/

engineers/homepage

❍ National Crime Prevention Institute 

http://www.louisville.edu/a-s/ja/ncpi/courses.htm

❍ National Fire Protection Association 

http://www.nfpa.org

❍ National Institute of Building Sciences (NIBS) 

http://www.nibs.org and http://www.wbdg.org

❍ National Park Service, Denver Service Center 

http://www.nps.gov/dsc

❍ National Precast Concrete Association 

http://www.precast.org
ASSOCIATIONS AND ORGANIZATIONS E-9

❍ National Wilderness Training Center, Inc.

http://www.wildernesstraining.net

❍ New York City Office of Emergency Preparedness 

http://www.nyc.gov/html/oem

❍ Ohio State University 

http://www.osu.edu/homelandsecurity

❍ Pentagon Renovation Program 

http://renovation.pentagon.mil

❍ Portland Cement Association (PCA) 

http://www.portcement.org

❍ Primary Glass Manufacturers Council 

http://www.primaryglass.org

❍ Protective Glazing Council 

http://www.protectiveglazing.org

❍ Protective Technology Center at Penn State University 

http://www.ptc.psu.edu

❍ SAVE International 

http://www.value-eng.org

❍ Society of Fire Protection Engineers 

http://www.sfpe.org

❍ Southern Building Code Congress, International 

http://www.sbcci.org

❍ Sustainable Buildings Industry Council 

http://www.sbicouncil.org

❍ Transit Standards Consortium 

http://www.tsconsortium.org

❍ Transportation Research Board/Marine Board 

http://www.trb.org

❍ Transportation Security Administration - Maritime and Land 

http://www.tsa.dot.gov
E-10 ASSOCIATIONS AND ORGANIZATIONS 

❍ University of Missouri, Department of Civil & Environmental

Engineering, National Center for Explosion Resistant Design 

http://www.engineering.missouri.edu/explosion.htm

❍ U.S. Air Force Civil Engineer Support Agency

http://www.afcesa.af.mil

❍ U.S. Coast Guard 

http://www.uscg.mil

❍ U.S. Department of Energy 

http://www.energy.gov

• Sandia National Laboratories (SNL) 

http://www.sandia.gov

• Architectural Surety Program 

http://www.sandia.gov/archsur

• Critical Infrastructure Protection Initiative 

http://www.sandia.gov/LabNews/LN02-11-00/steam_

story.html

❍ U.S. Department of Health and Human Services 

http://www.hhs.gov

❍ U.S. Department of Veterans Affairs (VA) 

http://www.va.gov/facmgt

❍ U.S. Environmental Protection Agency (EPA), Chemical 

Emergency Preparedness and Prevention Office (CEPPO)–

Counter-terrorism 

http://www.epa.gov/swercepp/cntr-ter.html

❍ U.S. General Services Administration (GSA) 

http://www.gsa.gov

• Office of Federal Protective Service (FPS) of GSA 

http://www.gsa.gov/Portal/content/orgs_content.jsp?cont

entOID=117945&contentType=1005&P=1&S=1

• Office of Public Building Service (PBS) of GSA 

http://www.gsa.gov/Portal/content/orgs_content.jsp?cont

entOID=22883&contentType=1005&PPzz=1&S=1
ASSOCIATIONS AND ORGANIZATIONS E-11

• Office of the Chief Architect of GSA 

http://www.gsa.gov/Portal/content/orgs_content.jsp?cont

entOID=22899&contentType=1005

and 

http://www.oca.gsa.gov

❍ U.S. Green Building Council 

http://www.usgbc.org

❍ U.S. Marine Corps Headquarters 

http://www.usmc.mil

❍ U.S. Society on Dams 

http://www.ussdams.org

❍ Virginia Polytechnic Institute and State University 

http://www.ce.vt.edu

❍ Water and Wastewater Equipment Manufacturers Association 

http://www.wwema.org

The Partnership for Critical Infrastructure (PCIS) 

http://www.pcis.org

Note: Involved mainly with information systems and not building 

real property.

Government

❍ Department of Commerce Critical Infrastructure Assurance 

Office (CIAO) 

http://www.ciao.gov

❍ Department of Energy (DOE) 

http://www.energy.gov

❍ Department of Homeland Security 

http://www.whitehouse.gov/deptofhomeland

❍ National Infrastructure Protection Center (NIPC) 

http://www.nipc.gov
E-12 ASSOCIATIONS AND ORGANIZATIONS 

Private Sector

❍ Anser Institute for Homeland Security (ANSER) 

http://www.homelandsecurity.org

❍ CERT® Coordination Center (CERT/CC) 

http://www.cert.org

❍ Electronic Warfare Associates (EWA) 

http://www.ewa.com

❍ Information Technology Association of America (ITAA) 

http://www.itaa.org

❍ National Cyber Security Alliance (Alliance) 

http://www.staysafeonline.info

❍ North American Electric Reliability Council (NERC) 

http://www.nerc.com

❍ SANS Institute (SANS - SysAdmin, Audit, Network, Security) 

http://www.sans.org

❍ The Financial Services Roundtable Technology Group (BITS) 

http://www.bitsinfo.org

❍ The Institute for Internal Auditors (IIA) 

http://www.theiia.org

❍ The U.S. Chamber of Commerce, Center for Corporate 

Citizenship (CCC) 

http://www.uschamber.com/ccc

Selected States and Local Organizations

❍ Association of Metropolitan Water Agencies 

http://www.amwa.net

❍ International Association of Emergency Managers (IAEM) 

http://www.iaem.com

❍ National Association of State CIOs (NASCIO) 

http://www.nascio.org
ASSOCIATIONS AND ORGANIZATIONS E-13

❍ National Emergency Managers Association (NEMA) 

http://www.nemaweb.org

❍ National Governor’s Association (NGA) 

http://www.csg.org

❍ The Council of State Governments (CSG) 

http://www.csg.org

❍ The National League of Cities (NLC) 

http://www.nlc.org

BUILDING VULNERABILITY ASSESSMENT CHECKLIST F

BUILDING VULNERABILITY ASSESSMENT CHECKLIST F-1

T he Building Vulnerability Assessment Checklist is 

based on the checklist developed by the Department 

of Veterans Affairs (VA) and compiles many best practices based on technologies and scientific research to consider 

during the design of a new school building or renovation of an 

existing building. It allows a consistent security evaluation of designs at various levels. The checklist can be used as a screening 

tool for preliminary design vulnerability assessment or be used 

by subject matter experts for a comprehensive vulnerability assessment of existing buildings. In addition to examining design 

issues that affect vulnerability, the checklist includes questions 

that determine if critical systems continue to function in order 

to enhance deterrence, detection, denial, and damage limitation, and to ensure that emergency systems function during a 

threat or hazard situation.

The checklist is organized into the 13 sections listed below. 

To conduct a vulnerability assessment of a school building or 

preliminary design, each section of the checklist should be assigned to an engineer, architect, or subject matter expert who 

is knowledgeable and qualified to perform an assessment of the 

assigned area. Each assessor should consider the questions and 

guidance provided to help identify vulnerabilities and document results in the observations column. If assessing an existing 

building, vulnerabilities can also be documented with photographs, if possible. The results of the 13 assessments should be 

integrated into a master vulnerability assessment and provide 

a basis for determining vulnerability ratings during the assessment process. 
1 Site

Section Vulnerability Question Guidance Observations

Critical infrastructure to consider includes:

Telecommunications infrastructure

Facilities for broadcast TV, cable TV; cellular 

networks; newspaper offices, production, and 

distribution; radio stations; satellite base stations; 

telephone trunking and switching stations, including 

critical cable routes and major rights-of-way

Electric power systems

Power plants, especially nuclear facilities; transmission 

and distribution system components; fuel distribution, 

delivery, and storage

Gas and oil facilities

Hazardous material facilities, oil/gas pipelines, and 

storage facilities

1.1

F-2 BUILDING VULNERABILITY ASSESSMENT CHECKLIST 

1. Site

2. Architectural

3. Structural Systems

4. Building Envelope

5. Utility Systems

6. Mechanical Systems (heating, ventilation, and air conditioning (HVAC) and CBR)

7. Plumbing and Gas Systems

8. Electrical Systems

9. Fire Alarm Systems

10. Communications and Information Technology (IT) Systems

11. Equipment Operations and Maintenance

12. Security Systems

13. Security Master Plan

Building Vulnerablilty Assessment Checklist*

What major structures surround 

the facility (site or building(s))?

What critical infrastructure, 

government, military, or 

recreation facilities are in the local 

area that impact transportation, 

utilities, and collateral damage 

(attack at this facility impacting 

the other major structures or 

attack on the major structures 

impacting this facility)?

What are the adjacent land 

uses immediately outside the 

perimeter of this facility (site or 

building(s))?
Building Vulnerablilty Assessment Checklist* (continued)

Section Vulnerability Question Guidance Observations

BUILDING VULNERABILITY ASSESSMENT CHECKLIST F-3

Do future development plans 

change these land uses outside 

the facility (site or building (s)) 

perimeter? 

Although this question bridges 

threat and vulnerability, the threat 

is the manmade hazard that can 

occur (likelihood and impact) and 

the vulnerability is the proximity of 

the hazard to the building(s) being 

assessed. Thus, a chemical plant 

release may be a threat/hazard, but 

vulnerability changes if the plant is 1 

mile upwind for the prevailing winds 

versus 10 miles away and downwind. 

Similarly, a terrorist attack upon an 

adjacent building may impact the 

building(s) being assessed. The Murrah 

Federal Building in Oklahoma City was 

not the only building to have severe 

damage caused by the explosion of the 

Ryder rental truck bomb.

Banking and finance institutions

Financial institutions (banks, credit unions) and the 

business district; note schedule business/financial 

district may follow; armored car services

Transportation networks

Airports: carriers, flight paths, and airport layout; 

location of air traffic control towers, runways, 

passenger terminals, and parking areas

Bus Stations

Pipelines: oil; gas

Trains/Subways: rails and lines, railheads/rail 

yards, interchanges, tunnels, and cargo/passenger 

terminals; note hazardous material transported

Traffic: interstate highways/roads/tunnels/bridges 

carrying large volumes; points of congestion; note 

time of day and day of week

Trucking: hazardous materials cargo loading/

unloading facilities; truck terminals, weigh stations, 

and rest areas

Waterways: dams; levees; berths and ports for 

cruise ships, ferries, roll-on/roll-off cargo vessels, 

and container ships; international (foreign) flagged 

vessels (and cargo)

Water supply systems

Pipelines and process/treatment facilities, dams for 

water collection; wastewater treatment 

Government services

Federal/state/local government offices – post 

offices, law enforcement stations, fire/rescue, 

town/city hall, local mayor’s/governor’s residences, 

judicial offices and courts, military installations 

(include type-Active, Reserves, National Guard)

Emergency services

Backup facilities, communications centers, 

Emergency Operations Centers (EOCs), fire/

Emergency Medical Service (EMS) facilities, 

Emergency Medical Center (EMCs), law enforcement 

facilities
Building Vulnerablilty Assessment Checklist* (continued)

Section Vulnerability Question Guidance Observations

F-4 BUILDING VULNERABILITY ASSESSMENT CHECKLIST 

The following are not critical infrastructure, but 

have potential collateral damage to consider: 

Agricultural facilities: chemical distribution, 

storage, and application sites; crop spraying services; 

farms and ranches; food processing, storage, and 

distribution facilities

Commercial/manufacturing/industrial 

facilities: apartment buildings; business/corporate 

centers; chemical plants (especially those with Section 

302 Extremely Hazardous Substances); factories; 

fuel production, distribution, and storage facilities; 

hotels and convention centers; industrial plants; 

raw material production, distribution, and storage 

facilities; research facilities and laboratories; shipping, 

warehousing, transfer, and logistical centers

Events and attractions: festivals and 

celebrations; open-air markets; parades; rallies, 

demonstrations, and marches; religious services; 

scenic tours; theme parks

Health care system components: family 

planning clinics; health department offices; 

hospitals; radiological material and medical waste 

transportation, storage, and disposal; research 

facilities and laboratories, walk-in clinics

Political or symbolically significant sites: 

embassies, consulates, landmarks, monuments, political 

party and special interest groups offices, religious sites

Public/private institutions: academic 

institutions, cultural centers, libraries, museums, 

research facilities and laboratories, schools

Recreation facilities: auditoriums, casinos, 

concert halls and pavilions, parks, restaurants and 

clubs (frequented by potential target populations), 

sports arenas, stadiums, theaters, malls, and special 

interest group facilities; note congestion dates and 

times for shopping centers

References: FEMA 386-7, FEMA SLG 101, 

DOJ NCJ181200

Depressions or low areas can trap heavy vapors, inhibit 

natural decontamination by prevailing winds, and reduce 

the effectiveness of in-place sheltering.

Reference: USAF Installation Force Protection Guide

1.2 Does the terrain place the 

building in a depression or low 

area?
Building Vulnerablilty Assessment Checklist* (continued)

Section Vulnerability Question Guidance Observations

BUILDING VULNERABILITY ASSESSMENT CHECKLIST F-5

1.3 In dense, urban areas, does curb 

lane parking allow uncontrolled 

vehicles to park unacceptably 

close to a building in public 

rights-of-way?

Where distance from the building to the nearest curb 

provides insufficient setback, restrict parking in the curb 

lane. For typical city streets, this may require negotiating 

to close the curb lane. Setback is common terminology 

for the distance between a building and its associated 

roadway or parking. It is analogous to stand-off between 

a vehicle bomb and the building. The benefit per foot of 

increased stand-off between a potential vehicle bomb 

and a building is very high when close to a building and 

decreases rapidly as the distance increases. Note that the 

July 1, 1994, Americans with Disabilities Act Standards 

for Accessible Design states that required handicapped 

parking shall be located on the shortest accessible 

route of travel from adjacent parking to an accessible 

entrance.

Reference: GSA PBS-P100

The intent is to channel pedestrian traffic onto a site with 

multiple buildings through known access control points. 

For a single building, the intent is to have a single visitor 

entrance.

Reference: GSA PBS-P100

The goal is to have at least two access points – one for 

passenger vehicles and one for delivery trucks due to the 

different procedures needed for each. Having two access 

points also helps if one of the access points becomes 

unusable, then traffic can be routed through the other 

access point.

Reference: USAF Installation Force Protection Guide

Pedestrian access should not be endangered by car 

traffic. Pedestrian access, especially from public 

transportation, should not cross vehicle traffic if possible.

References: GSA PBS-P100 and FEMA 386-7

Vehicle and pedestrian access control and inspection 

should occur as far from facilities as possible (preferably 

at the site perimeter) with the ability to regulate the flow 

of people and vehicles one at a time.

Control on-site parking with identification checks, 

security personnel, and access control systems.

Reference: FEMA 386-7

1.4

1.5

1.6

Is a perimeter fence or other 

types of barrier controls in 

place?

What are the site access points 

to the site or building?

Is vehicle traffic separated from 

pedestrian traffic on the site?

1.7 Is there vehicle and pedestrian 

access control at the perimeter 

of the site?
Building Vulnerablilty Assessment Checklist* (continued)

Section Vulnerability Question Guidance Observations

F-6 BUILDING VULNERABILITY ASSESSMENT CHECKLIST 

Design features for the vehicular inspection point 

include: vehicle arrest devices that prevent vehicles 

from leaving the vehicular inspection area and prevent 

tailgating.

If screening space cannot be provided, consider other 

design features such as: hardening and alternative 

location for vehicle search/inspection.

Reference: GSA PBS-P100 

Eliminate potential site access through utility tunnels, 

corridors, manholes, stormwater runoff culverts, etc. 

Ensure covers to these access points are secured.

Reference: USAF Installation Force Protection Guide

Passive barriers include bollards, walls, hardened 

fences (steel cable interlaced), trenches, ponds/basins, 

concrete planters, street furniture, plantings, trees, 

sculptures, and fountains. Active barriers include popup bollards, swing arm gates, and rotating plates and 

drums, etc.

Reference: GSA PBS-P100

If the recommended distance for the postulated 

threat is not available, consider reducing the 

stand-off required through structural hardening or 

manufacturing additional stand-off through barriers 

and parking restrictions. Also, consider relocation of 

vulnerable functions within the building, or to a more 

hazard-resistant building. More stand-off should be 

used for unscreened vehicles than for screened vehicles 

that have been searched.

Reference: GSA PBS-P100

Anti-ram protection may be provided by adequately 

designed: bollards, street furniture, sculpture, 

landscaping, walls, and fences. The anti-ram protection 

must be able to stop the threat vehicle size (weight) at 

the speed attainable by that vehicle at impact. If the 

anti-ram protection cannot absorb the desired kinetic 

energy, consider adding speed controls (serpentines 

or speed bumps) to limit the speed at impact. If the 

resultant speed is still too great, the anti-ram protection 

should be improved.

References: Military Handbook 1013/14 and 

GSA PBS P-100

1.8 Is there space for inspection 

at the curb line or outside the 

protected perimeter?

What is the minimum distance 

from the inspection location to 

the building?

1.9 Is there any potential access 

to the site or building through 

utility paths or water runoff?

1.10 What are the existing types of 

vehicle anti-ram devices for the 

site or building?

Are these devices at the 

property boundary or at the 

building?

1.11 What is the anti-ram buffer 

zone stand-off distance from the 

building to unscreened vehicles 

or parking?

1.12 Are perimeter barriers capable 

of stopping vehicles?

Will the vehicle barriers at 

the perimeter and building 

maintain access for emergency 

responders, including large fire 

apparatus?
Building Vulnerablilty Assessment Checklist* (continued)

Section Vulnerability Question Guidance Observations

BUILDING VULNERABILITY ASSESSMENT CHECKLIST F-7

The intent is to use site circulation to minimize vehicle 

speeds and eliminate direct approaches to structures.

Reference: GSA PBS-P100

Single or double 90-degree turns effectively reduce 

vehicle approach speed.

Reference: GSA PBS-P100

Adjacent public parking should be directed to more distant 

or better-protected areas, segregated from employee 

parking and away from the building. Some publications 

use the term setback in lieu of the term stand-off.

Reference: GSA PBS-P100

The specific stand-off distance needed is based upon 

the design basis threat bomb size and the building 

construction. For initial screening, consider using 25 

meters (82 feet) as a minimum, with more distance 

needed for unreinforced masonry or wooden walls.

Reference: GSA PBS-P100

Pedestrian paths should be planned to concentrate activity 

to the extent possible.

Limiting vehicular entry/exits to a minimum number of 

locations is beneficial.

Stair tower and elevator lobby design should be as open 

as code permits. Stair and/or elevator waiting areas 

should be as open to the exterior and/or the parking 

areas as possible and well lighted. Impact-resistant, 

laminated glass for stair towers and elevators is a way to 

provide visual openness.

Potential hiding places below stairs should be closed off; 

nooks and crannies should be avoided, and dead-end 

parking areas should be eliminated.

Reference: GSA PBS-P100

Control internal building parking, underground parking 

garages, and access to service areas and loading docks in 

this manner with proper access control, or eliminate the 

parking altogether.

The anti-ram device must be capable of arresting a vehicle 

of the designated threat size at the speed attainable at 

the location.

Reference: GSA PBS-P100

1.13 Does site circulation prevent 

high-speed approaches by 

vehicles?

1.14 Are there offsetting vehicle 

entrances from the direction of 

a vehicle’s approach to force a 

reduction of speed?

1.15 Is there a minimum setback 

distance between the building 

and parked vehicles?

1.16 Does adjacent surface parking 

on site maintain a minimum 

stand-off distance?

1.17 Do standalone, aboveground 

parking garages provide 

adequate visibility across as 

well as into and out of the 

parking garage?

1.18 Are garage or service area 

entrances for employeepermitted vehicles protected by 

suitable anti-ram devices?

Coordinate this protection with 

other anti-ram devices, such as 

on the perimeter or property 

boundary to avoid duplication of 

arresting capability.
Building Vulnerablilty Assessment Checklist* (continued)

Section Vulnerability Question Guidance Observations

F-8 BUILDING VULNERABILITY ASSESSMENT CHECKLIST 

Minimize concealment opportunities by keeping 

landscape plantings (hedges, shrubbery, and large 

plants with heavy ground cover) and street furniture 

(bus shelters, benches, trash receptacles, mailboxes, 

newspaper vending machines) away from the building 

to permit observation of intruders and prevent hiding 

of packages.

If mail or express boxes are used, the size of the 

openings should be restricted to prohibit the insertion 

of packages.

Reference: GSA PBS-P100

Security protection can be successfully addressed 

through adequate lighting. The type and design 

of lighting, including illumination levels, is critical. 

Illuminating Engineering Society of North America 

(IESNA) guidelines can be used. The site lighting should 

be coordinated with the CCTV system.

Reference: GSA PBS-P100

The goal is to prevent the observation of critical assets 

by persons outside the secure boundary of the site. For 

individual buildings in an urban environment, this could 

mean appropriate window treatments or no windows for 

portions of the building.

Once on the site, the concern is to ensure observation 

by a general workforce aware of any pedestrians or 

vehicles outside normal circulation routes or attempting 

to approach the building unobserved.

Reference: USAF Installation Force Protection Guide

The signage should be simple and have the necessary 

level of clarity. However, signs that identify sensitive 

areas should generally not be provided.

Reference: GSA PBS-P100

Just as vehicle access points to the site must be able to 

transit emergency vehicles, so too must the emergency 

vehicles have access to the buildings and, in the 

case of fire trucks, the fire hydrants. Thus, security 

considerations must accommodate emergency response 

requirements.

Reference: GSA PBS-P100

1.19 Do site landscaping and street 

furniture provide hiding places?

1.20 Is the site lighting adequate 

from a security perspective in 

roadway access and parking 

areas?

1.21 Are line-of-sight perspectives 

from outside the secured 

boundary to the building and on 

the property along pedestrian 

and vehicle routes integrated 

with landscaping and green 

space?

1.22 Do signs provide control of 

vehicles and people?

1.23 Are all existing fire hydrants on 

the site accessible?
Building Vulnerablilty Assessment Checklist* (continued)

Section Vulnerability Question Guidance Observations

BUILDING VULNERABILITY ASSESSMENT CHECKLIST F-9

The focus of CPTED is on creating defensible space 

by employing:

1. Natural access controls:

– Design streets, sidewalks, and building entrances to 

clearly indicate public routes and direct people away 

from private/restricted areas

– Discourage access to private areas with structural 

elements and limit access (no cut-through streets)

– Loading zones should be separate from public parking

2. Natural surveillance:

– Design that maximizes visibility of people, parking 

areas, and building entrances; doors and windows 

that look out on to streets and parking areas

– Shrubbery under 2 feet in height for visibility

– Lower branches of existing trees kept at least 10 

feet off the ground

– Pedestrian-friendly sidewalks and streets to control 

pedestrian and vehicle circulation

– Adequate nighttime lighting, especially at exterior 

doorways

3. Territorial reinforcement:

– Design that defines property lines

– Design that distinguishes private/restricted spaces 

from public spaces using separation, landscape 

plantings; pavement designs (pathway and roadway 

placement); gateway treatments at lobbies, 

corridors, and door placement; walls, barriers, 

signage, lighting, and “CPTED” fences

– “Traffic-calming” devices for vehicle speed control

4. Target hardening:

– Prohibit entry or access: window locks, deadbolts for 

doors, interior door hinges

– Access control (building and employee/visitor 

parking) and intrusion detection systems

5. Closed circuit television cameras:

– Prevent crime and influence positive behavior, while 

enhancing the intended uses of space. In other 

words, design that eliminates or reduces criminal 

behavior and at the same time encourages people 

to “keep an eye out” for each other.

References: GSA PBS-P100 and FEMA 386-7

2.1 Does the site and architectural 

design incorporate strategies 

from a Crime Prevention 

Through Environmental Design 

(CPTED) perspective?

2 Architectural 
Building Vulnerablilty Assessment Checklist* (continued)

Section Vulnerability Question Guidance Observations

F-10 BUILDING VULNERABILITY ASSESSMENT CHECKLIST 

Separate high-risk tenants from low-risk tenants and 

from publicly accessible areas. Mixed uses may be 

accommodated through such means as separating 

entryways, controlling access, and hardening shared 

partitions, as well as through special security operational 

countermeasures.

Reference: GSA PBS-P100

Site planning and landscape design can provide natural 

surveillance by concentrating pedestrian activity, 

limiting entrances/exits, and eliminating concealment 

opportunities. Also, prevent pedestrian access to parking 

areas other than via established entrances.

Reference: GSA PBS-P100

The size of the trash receptacles and mailbox openings 

should be restricted to prohibit insertion of packages. 

Street furniture, such as newspaper vending machines, 

should be kept sufficient distance (10 meters or 33 feet) 

from the building, or brought inside to a secure area.

References: USAF Installation Force Protection Guide and 

DoD UCF 4-010-01

If queuing will occur within the building footprint, the 

area should be enclosed in blast-resistant construction. 

If queuing is expected outside the building, a rain cover 

should be provided. For manpower and equipment 

requirements, collocate or combine staff and visitor 

entrances.

Reference: GSA PBS-P100

Retail activities should be prohibited in non-secured 

areas. However, the Public Building Cooperative Use Act 

of 1976 encourages retail and mixed uses to create open 

and inviting buildings. Consider separating entryways, 

controlling access, hardening shared partitions, and 

special security operational countermeasures.

References: GSA PBS-P100 and FEMA 386-7

2.2 Is it a mixed-tenant building?

2.3 Are pedestrian paths planned 

to concentrate activity to aid in 

detection?

2.4 Are there trash receptacles and 

mailboxes in close proximity to 

the building that can be used to 

hide explosive devices?

2.5 Do entrances avoid significant 

queuing?

2.6 Does security screening cover all 

public and private areas?

Are public and private activities 

separated?

Are public toilets, service 

spaces, or access to stairs or 

elevators located in any nonsecure areas, including the 

queuing area before screening at 

the public entrance?
Building Vulnerablilty Assessment Checklist* (continued)

Section Vulnerability Question Guidance Observations

BUILDING VULNERABILITY ASSESSMENT CHECKLIST F-11

2.7 Is access control provided 

through main entrance points for 

employees and visitors?

(lobby receptionist, sign-in, staff escorts, 

issue of visitor badges, checking forms of 

personal identification, electronic access 

control systems)

Reference: Physical Security Assessment for the 

Department of Veterans Affairs Facilities

Finishes and signage should be designed for visual 

simplicity.

Reference: Physical Security Assessment for the 

Department of Veterans Affairs Facilities

Reference: Physical Security Assessment for the 

Department of Veterans Affairs Facilities

These include walk-through metal detectors and x-ray 

devices, identification check, electronic access card, 

search stations, and turnstiles.

Reference: GSA PBS-P100

Consider for exterior entrances to the building or to 

access critical areas within the building if explosive blast 

hazard must be mitigated.

Reference: U.S. Army TM 5-853 

If the postulated threat in designing entrance access 

control includes rifles, pistols, or shotguns, then the 

screening area should have bullet-resistance to protect 

security personnel and uninvolved bystanders. Glass, if 

present, should also be bullet-resistant.

Reference: GSA PBS-P100

This applies to building entrances and to critical areas 

within the building.

References: USAF Installation Force Protection Guide and 

DoD UFC 4-010-01

2.8 Is access to private and public 

space or restricted area space 

clearly defined through the design 

of the space, signage, use of 

electronic security devices, etc.?

2.9 Is access to elevators 

distinguished as to those that are 

designated only for employees 

and visitors?

2.10 Do public and employee entrances 

include space for possible future 

installation of access control and 

screening equipment?

2.11 Do foyers have reinforced 

concrete walls and offset interior 

and exterior doors from each 

other?

2.12 Do doors and walls along the 

line of security screening meet 

requirements of UL752 “Standard 

for Safety: Bullet-Resisting 

Equipment”?

2.13 Do circulation routes have 

unobstructed views of people 

approaching controlled access 

points?
Building Vulnerablilty Assessment Checklist* (continued)

Section Vulnerability Question Guidance Observations

F-12 BUILDING VULNERABILITY ASSESSMENT CHECKLIST 

References: GSA PBS-P100 and CDC/NIOSH, 

Pub 2002-139

Critical building components include: Emergency 

generator including fuel systems, day tank, fire sprinkler, 

and water supply; Normal fuel storage; Main switchgear; 

Telephone distribution and main switchgear; Fire 

pumps; Building control centers; Uninterruptible Power 

Supply (UPS) systems controlling critical functions; Main 

refrigeration and ventilation systems if critical to building 

operation; Elevator machinery and controls; Shafts for 

stairs, elevators, and utilities; Critical distribution feeders 

for emergency power. Evacuation and rescue require 

emergency systems to remain operational during a 

disaster and they should be located away from potential 

attack locations. Primary and backup systems should 

be separated to reduce the risk of both being impacted 

by a single incident if collocated. Utility systems should 

be located at least 50 feet from loading docks, front 

entrances, and parking areas.

One way to harden critical building systems and 

components is to enclose them within hardened walls, 

floors, and ceilings. Do not place them near high-risk areas 

where they can receive collateral damage.

Reference: GSA PBS-P100

Critical assets, such as people and activities, are more 

vulnerable to hazards when on an exterior building 

wall or adjacent to uncontrolled public areas inside the 

building.

Reference: GSA PBS-P100

High-risk activities should also be separated from low-risk 

activities. Also, visitor activities should be separated from 

daily activities.

Reference: USAF Installation Force Protection Guide

Reference: USAF Installation Force Protection Guide

2.14 Is roof access limited to 

authorized personnel by means 

of locking mechanisms?

2.15 Are critical assets (people, 

activities, building systems 

and components) located close 

to any main entrance, vehicle 

circulation, parking, maintenance 

area, loading dock, or interior 

parking?

Are the critical building systems 

and components hardened?

2.16 Are high-value or critical assets 

located as far into the interior 

of the building as possible and 

separated from the public areas 

of the building?

2.17 Is high visitor activity away 

from critical assets?

2.18 Are critical assets located in 

spaces that are occupied 24 

hours per day?

Are assets located in areas 

where they are visible to more 

than one person?
Building Vulnerablilty Assessment Checklist* (continued)

Section Vulnerability Question Guidance Observations

BUILDING VULNERABILITY ASSESSMENT CHECKLIST F-13

Loading docks should be designed to keep vehicles from 

driving into or parking under the building. If loading 

docks are in close proximity to critical equipment, 

consider hardening the equipment and service against 

explosive blast. Consider a 50-foot separation distance in 

all directions.

Reference: GSA PBS-P100

The mailroom should be located at the perimeter of the 

building with an outside wall or window designed for 

pressure relief.

By separating the mailroom and the loading dock, the 

collateral damage of an incident at one has less impact 

upon the other. However, this may be the preferred 

mailroom location.

Off-site screening stations or a separate delivery 

processing building on site may be cost-effective, 

particularly if several buildings may share one mailroom. 

A separate delivery processing building reduces risk and 

simplifies protection measures.

Reference: GSA PBS-P100

Screening of all deliveries to the building, including U.S. 

mail, commercial package delivery services, delivery of 

office supplies, etc.

Reference: GSA PBS-P100

Areas of refuge can be safe havens, shelters, or protected 

spaces for use during specified hazards.

Reference: FEMA 386-7

Consider designing stairs so that they discharge into areas 

other than lobbies, parking, or loading docks.

Maintaining positive pressure from a clean source of air 

(may require special filtering) aids in egress by keeping 

smoke, heat, toxic fumes, etc,. out of the stairway. 

Pressurize exit stairways in accordance with the National 

Model Building Code.

References: GSA PBS-P100 and CDC/NIOSH, 

Pub 2002-139

2.19 Are loading docks and receiving 

and shipping areas separated 

in any direction from utility 

rooms, utility mains, and service 

entrances, including electrical, 

telephone/data, fire detection/

alarm systems, fire suppression 

water mains, cooling and heating 

2.20 Are mailrooms located away 

from building main entrances, 

areas containing critical services, 

utilities, distribution systems, and 

important assets?

Is the mailroom located near the 

loading dock?

2.21 Does the mailroom have adequate 

space available for equipment 

to examine incoming packages 

and for an explosive disposal 

2.22 Are areas of refuge identified, 

with special consideration given to 

egress?

2.23 Are stairwells required for 

emergency egress located as 

remotely as possible from highrisk areas where blast events 

might occur?

Are stairways maintained with 

positive pressure or are there 

other smoke control systems?
Building Vulnerablilty Assessment Checklist* (continued)

Section Vulnerability Question Guidance Observations

F-14 BUILDING VULNERABILITY ASSESSMENT CHECKLIST 

Egress pathways should be hardened and discharge into 

safe areas.

Reference: FEMA 386-7

Reference: USAF Installation Force Protection Guide

The intent is to keep the emergency systems out of 

harm’s way, such that one incident does not take out all 

capability – both the regular systems and their backups.

Reference: FEMA 386-7

Interior glazing should be minimized where a threat 

exists and should be avoided in enclosures of critical 

functions next to high-risk areas.

Reference: GSA PBS-P100

When an explosive blast shatters a window, the blast 

wave enters the interior space, putting structural and 

non-structural building components under loads not 

considered in standard building codes. It has been 

shown that connection criteria for these systems in high 

seismic activity areas resulted in much less falling debris 

that could injure building occupants.

Mount all overhead utilities and other fixtures weighing 

14 kilograms (31 pounds) or more to minimize 

the likelihood that they will fall and injure building 

occupants. Design all equipment mountings to resist 

forces of 0.5 times the equipment weight in any 

direction and 1.5 times the equipment weight in the 

downward direction. This standard does not preclude the 

need to design equipment mountings for forces required 

by other criteria, such as seismic standards.

Reference: DoD UCF 4-101-01

2.25 Do interior barriers differentiate 

level of security within a 

building?

2.26 Are emergency systems located 

away from high-risk areas?

2.27 Is interior glazing near high-risk 

areas minimized?

Is interior glazing in other areas 

shatter-resistant?

2.28 Are ceiling and lighting systems 

designed to remain in place 

during hazard events?

2.24 Are enclosures for emergency 

egress hardened to limit the 

extent of debris that might 

otherwise impede safe passage 

and reduce the flow of evacuees? 
Building Vulnerablilty Assessment Checklist* (continued)

Section Vulnerability Question Guidance Observations

BUILDING VULNERABILITY ASSESSMENT CHECKLIST F-15

3.1 The type of construction provides an indication of the 

robustness to abnormal loading and load reversals. A 

reinforced concrete moment-resisting frame provides 

greater ductility and redundancy than a flat-slab or 

flat-plate construction. The ductility of steel frame 

with metal deck depends on the connection details and 

pre-tensioned or post-tensioned construction provides 

little capacity for abnormal loading patterns and load 

reversals. The resistance of load-bearing wall structures 

varies to a great extent, depending on whether the walls 

are reinforced or un-reinforced. A rapid screening process 

developed by FEMA for assessing structural hazards 

identifies the following types of construction with a 

structural score ranging from 1.0 to 8.5. A higher score 

indicates a greater capacity to sustain load reversals.

Wood buildings of all types - 4.5 to 8.5

Steel moment-resisting frames - 3.5 to 4.5

Braced steel frames - 2.5 to 3.0

Light metal buildings - 5.5 to 6.5

Steel frames with cast-in-place concrete 

shear walls - 3.5 to 4.5

Steel frames with unreinforced masonry 

infill walls - 1.5 to 3.0

Concrete moment-resisting frames - 2.0 to 4.0

Concrete shear wall buildings - 3.0 to 4.0

Concrete frames with unreinforced masonry 

infill walls - 1.5 to 3.0

Tilt-up buildings - 2.0 to 3.5

Precast concrete frame buildings - 1.5 to 2.5

Reinforced masonry - 3.0 to 4.0

Unreinforced masonry - 1.0 to 2.5

References: FEMA 154 and Physical Security Assessment 

for the Department of Veterans Affairs Facilities

Reference: GSA PBS-P100

What type of construction?

What type of concrete and 

reinforcing steel?

What type of steel?

What type of foundation?

Do the reinforced concrete 

structures contain symmetric 

steel reinforcement (positive and 

negative faces) in all floor slabs, 

roof slabs, walls, beams, and 

girders that may be subjected 

to rebound, uplift, and suction 

pressures?

3.2

3 Structural Systems 
Building Vulnerablilty Assessment Checklist* (continued)

Section Vulnerability Question Guidance Observations

F-16 BUILDING VULNERABILITY ASSESSMENT CHECKLIST 

3.3

Do the lap splices fully 

develop the capacity of the 

reinforcement?

Are lap splices and other 

discontinuities staggered?

Do the connections possess 

ductile details?

Is special shear reinforcement, 

including ties and stirrups, 

available to allow large postelastic behavior?

Are the steel frame connections 

moment connections?

Is the column spacing minimized 

so that reasonably sized 

members will resist the 

design loads and increase the 

redundancy of the system?

What are the floor-to-floor 

heights?

Are critical elements vulnerable 

to failure?

A practical upper level for column spacing is generally 

30 feet. Unless there is an overriding architectural 

requirement, a practical limit for floor-to-floor heights is 

generally less than or equal to 16 feet.

Reference: GSA PBS-P100

The priority for upgrades should be based on the relative 

importance of structural or non-structural elements that 

are essential to mitigating the extent of collapse and 

minimizing injury and damage.

Primary Structural Elements provide the essential parts 

of the building’s resistance to catastrophic blast loads 

and progressive collapse. These include columns, girders, 

roof beams, and the main lateral resistance system.

Secondary Structural Elements consist of all other loadbearing members, such as floor beams, slabs, etc.

Primary Non-Structural Elements consist of elements 

(including their attachments) that are essential for life 

safety systems or elements that can cause substantial 

injury if failure occurs, including ceilings or heavy 

suspended mechanical units.

Secondary Non-Structural Elements consist of all 

elements not covered in primary non-structural 

elements, such as partitions, furniture, and light fixtures.

Reference: GSA PBS-P100

3.4
Building Vulnerablilty Assessment Checklist* (continued)

Section Vulnerability Question Guidance Observations

BUILDING VULNERABILITY ASSESSMENT CHECKLIST F-17

The extent of damage to the structure and exterior 

wall systems from the bomb threat may be related to a 

protection level. The following is for new buildings: 

Level of Protection Below Antiterrorism 

Standards – Severe damage. Frame collapse/massive 

destruction. Little left standing. Doors and windows fail 

and result in lethal hazards. Majority of personnel suffer 

fatalities.

Very Low Level Protection – Heavy damage. Onset 

of structural collapse. Major deformation of primary and 

secondary structural members, but progressive collapse 

is unlikely. Collapse of non-structural elements. Glazing 

will break and is likely to be propelled into the building, 

resulting in serious glazing fragment injuries, but 

fragments will be reduced. Doors may be propelled into 

rooms, presenting serious hazards. Majority of personnel 

suffer serious injuries. There are likely to be a limited 

number (10 percent to 25 percent) of fatalities.

Low Level of Protection – Moderate damage, 

unrepairable. Major deformation of non-structural 

elements and secondary structural members and 

minor deformation of primary structural members, but 

progressive collapse is unlikely. Glazing will break, but 

fall within 1 meter of the wall or otherwise not present 

a significant fragment hazard. Doors may fail, but they 

will rebound out of their frames, presenting minimal 

hazards. Majority of personnel suffer significant injuries. 

There may be a few (<10 percent) fatalities.

Medium Level Protection – Minor damage, 

repairable. Minor deformations of non-structural 

elements and secondary structural members and no 

permanent deformation in primary structural members. 

Glazing will break, but will remain in the window frame. 

Doors will stay in frames, but will not be reusable. Some 

minor injuries, but fatalities are unlikely.

High Level Protection – Minimal damage, repairable. 

No permanent deformation of primary and secondary 

structural members or non-structural elements. Glazing 

will not break. Doors will be reusable. Only superficial 

injuries are likely.

Reference: DoD UFC 4-010-01

Design to mitigate progressive collapse is an independent 

analysis to determine a system’s ability to resist 

structural collapse upon the loss of a major structural 

element or the system’s ability to resist the loss of a 

major structural element. Design to mitigate progressive 

collapse may be based on the methods outlined in ASCE 

7-98 (now 7-02). Designers may apply static and/or 

Will the structure suffer an 

unacceptable level of damage 

resulting from the postulated 

threat (blast loading or weapon 

impact)? 

3.5

3.6 Is the structure vulnerable to 

progressive collapse?

Is the building capable of 

sustaining the removal of a column 

for one floor above grade at 
Building Vulnerablilty Assessment Checklist* (continued)

Section Vulnerability Question Guidance Observations

F-18 BUILDING VULNERABILITY ASSESSMENT CHECKLIST 

the building perimeter without 

progressive collapse?

In the event of an internal 

explosion in an uncontrolled public 

ground floor area, does the design 

prevent progressive collapse due 

to the loss of one primary column?

Do architectural or structural 

features provide a minimum 

6-inch stand-off to the internal 

columns (primary vertical load 

carrying members)?

Are the columns in the unscreened 

internal spaces designed for an 

unbraced length equal to two 

floors, or three floors where 

there are two levels of parking?

Are there adequate redundant 

load paths in the structure?

Are there transfer girders 

supported by columns within 

unscreened public spaces or at the 

exterior of the building?

What is the grouting and 

reinforcement of masonry (brick 

and/or concrete masonry unit 

(CMU)) exterior walls?

dynamic methods of analysis to meet this requirement 

and ultimate load capacities may be assumed in the 

analyses. Combine structural upgrades for retrofits 

to existing buildings, such as seismic and progressive 

collapse, into a single project due to the economic 

synergies and other cross benefits. Existing facilities may 

be retrofitted to withstand the design level threat or to 

accept the loss of a column for one floor above grade at 

the building perimeter without progressive collapse. Note 

that collapse of floors or roof must not be permitted.

Reference: GSA PBS-P100

Special consideration should be given to materials 

that have inherent ductility and that are better able to 

respond to load reversals, such as cast in place reinforced 

concrete, reinforced masonry, and steel construction.

Careful detailing is required for material such as prestressed concrete, pre-cast concrete, and masonry to 

adequately respond to the design loads. Primary vertical 

load carrying members should be protected where 

parking is inside a facility and the building superstructure 

is supported by the parking structure.

Reference: GSA PBS-P100

Transfer girders allow discontinuities in columns between 

the roof and foundation. This design has inherent 

difficulty in transferring load to redundant paths upon 

loss of a column or the girder. Transfer beams and girders 

that, if lost, may cause progressive collapse are highly 

discouraged.

Reference: GSA PBS-P100

Avoid unreinforced masonry exterior walls. 

Reinforcement can run the range of light to heavy, 

depending upon the stand-off distance available and 

postulated design threat.

Reference: GSA PBS-P100 recommends fully grouted and 

reinforced CMU construction where CMU is selected.

3.7

3.8

3.9
Building Vulnerablilty Assessment Checklist* (continued)

Section Vulnerability Question Guidance Observations

BUILDING VULNERABILITY ASSESSMENT CHECKLIST F-19

3.10 Will the loading dock design 

limit damage to adjacent areas 

and vent explosive force to the 

exterior of the building?

Are mailrooms, where packages 

are received and opened for 

inspection, and unscreened retail 

spaces designed to mitigate the 

effects of a blast on primary 

vertical or lateral bracing 

members?

Reference: DoD Minimum Antiterrorism Standards 

for Buildings states “Unreinforced masonry walls are 

prohibited for the exterior walls of new buildings. A 

minimum of 0.05 percent vertical reinforcement with a 

maximum spacing of 1200 mm (48 in) will be provided. 

For existing buildings, implement mitigating measures to 

provide an equivalent level of protection.” [This is light 

reinforcement and based upon the recommended standoff distance for the situation.] 

Design the floor of the loading dock for blast resistance if 

the area below is occupied or contains critical utilities.

Reference: GSA PBS-P100

Where mailrooms and unscreened retail spaces are 

located in occupied areas or adjacent to critical utilities, 

walls, ceilings, and floors, they should be blast- and 

fragment- resistant.

Methods to facilitate the venting of explosive forces 

and gases from the interior spaces to the outside of 

the structure may include blow-out panels and window 

system designs that provide protection from blast 

pressure applied to the outside, but that readily fail and 

vent if exposed to blast pressure on the inside.

Reference: GSA PBS-P100

3.11

What is the designed or 

estimated protection level of 

the exterior walls against the 

postulated explosive threat?

The performance of the façade varies to a great extent 

on the materials. Different construction includes brick or 

stone with block backup, steel stud walls, precast panels, 

or curtain wall with glass, stone, or metal panel elements.

Shear walls that are essential to the lateral and vertical 

load bearing system and that also function as exterior 

walls should be considered primary structures and should 

resist the actual blast loads predicted from the threats 

specified. Where exterior walls are not designed for the 

full design loads, special consideration should be given to 

construction types that reduce the potential for injury.

Reference: GSA PBS-P100

4.1

4 Building Envelope
Building Vulnerablilty Assessment Checklist* (continued)

Section Vulnerability Question Guidance Observations

F-20 BUILDING VULNERABILITY ASSESSMENT CHECKLIST 

Is there less than a 40 percent 

fenestration opening per 

structural bay?

Is the window system design on 

the exterior façade balanced to 

mitigate the hazardous effects 

of flying glazing following an 

explosive event? (glazing, 

frames, anchorage to supporting 

walls, etc.)

Do the glazing systems with a 1⁄2-

inch (3⁄4-inch is better) bite contain 

an application of structural silicone?

Is the glazing laminated or is it 

protected with an anti-shatter 

(fragment retention) film?

If an anti-shatter film is used, is 

it a minimum of a 7-mil thick film, 

or specially manufactured 4-mil 

thick film?

Do the walls, anchorage, and 

window framing fully develop the 

capacity of the glazing material 

selected?

Are the walls capable of 

withstanding the dynamic 

reactions from the windows?

Will the anchorage remain attached 

to the walls of the building during 

an explosive event without failure?

Is the façade connected to backup 

block or to the structural frame?

Are non-bearing masonry walls 

reinforced?

Does the building contain ballistic 

glazing?

The performance of the glass will similarly depend on the 

materials. Glazing may be single pane or double pane, 

monolithic or laminated, annealed, heat strengthened or 

fully tempered.

The percent fenestration is a balance between protection 

level, cost, the architectural look of the building within 

its surroundings, and building codes. One goal is to 

keep fenestration to below 40 percent of the building 

envelope vertical surface area, but the process must 

balance differing requirements. A blast engineer may 

prefer no windows; an architect may favor window 

curtain walls; building codes require so much fenestration 

per square footage of floor area; fire codes require 

a prescribed window opening area if the window is a 

designated escape route; and the building owner has cost 

concerns.

Ideally, an owner would want 100 percent of the 

glazed area to provide the design protection level 

against the postulated explosive threat (design basis 

threat– weapon size at the expected stand-off distance). 

However, economics and geometry may allow 80 percent 

to 90 percent due to the statistical differences in the 

manufacturing process for glass or the angle of incidence 

of the blast wave upon upper story windows (4th floor 

and higher).

Reference: GSA PBS-P100

Government produced and sponsored computer 

programs coupled with test data and recognized dynamic 

structural analysis techniques may be used to determine 

whether the glazing either survives the specified threats 

or the post damage performance of the glazing protects 

the occupants. A breakage probability no higher than 

750 breaks per 1,000 may be used when calculating 

loads to frames and anchorage.

The intent is to ensure the building envelope provides 

relatively equal protection against the postulated 

explosive threat for the walls and window systems for 

the safety of the occupants, especially in rooms with 

exterior walls.

Reference: GSA PBS-P100

Glass-clad polycarbonate or laminated polycarbonate are 

two types of acceptable glazing material.

4.3

4.4

4.2
Building Vulnerablilty Assessment Checklist* (continued)

Section Vulnerability Question Guidance Observations

BUILDING VULNERABILITY ASSESSMENT CHECKLIST F-21

Does the ballistic glazing meet the 

requirements of UL 752 BulletResistant Glazing?

Does the building contain securityglazing?

Does the security-glazing meet 

the requirements of ASTM F1233 

or UL 972, Burglary Resistant 

Glazing Material?

Do the window assemblies 

containing forced entry resistant 

glazing (excluding the glazing) meet 

the requirements of ASTM F 588?

Do non-window openings, such 

as mechanical vents and exposed 

plenums, provide the same level 

of protection required for the 

exterior wall?

If windows are upgraded to bullet-resistant, burglarresistant, or forced entry-resistant, ensure that doors, 

ceilings, and floors, as applicable, can resist the same for 

the areas of concern.

Reference: GSA PBS-P100

In-filling of blast over-pressures must be considered 

through non-window openings such that structural 

members and all mechanical system mountings and 

attachments should resist these interior fill pressures.

These non-window openings should also be as secure as 

the rest of the building envelope against forced entry.

Reference: GSA PBS-P100

4.5

What is the source of domestic 

water? (utility, municipal, wells, 

lake, river, storage tank)

Is there a secure alternate 

drinking water supply?

Are there multiple entry points for 

the water supply?

Is the incoming water supply in a 

secure location?

Does the building or site have 

storage capacity for domestic 

water?

5.1 Domestic water is critical for continued building 

operation. Although bottled water can satisfy 

requirements for drinking water and minimal sanitation, 

domestic water meets many other needs – flushing 

toilets, building heating and cooling system operation, 

cooling of emergency generators, humidification, etc.

Reference: FEMA 386-7

If the building or site has only one source of water 

entering at one location, the entry point should be 

secure.

Reference: GSA PBS-P100

Ensure that only authorized personnel have access to the 

water supply and its components.

Reference: FEMA 386-7

Operational facilities will require reliance on adequate 

domestic water supply. Storage capacity can meet 

short-term needs and use water trucks to replenish for 

extended outages.

5.2

5.3

5 Utility Systems

5.4
Building Vulnerablilty Assessment Checklist* (continued)

Section Vulnerability Question Guidance Observations

F-22 BUILDING VULNERABILITY ASSESSMENT CHECKLIST 

Reference: Physical Security Assessment for the 

Department of Veterans Affairs Facilities.

The fire suppression system water may be supplied from 

the domestic water or it may have a separate source, 

separate storage, or nonpotable alternate sources.

For a site with multiple buildings, the concern is that 

the supply should be adequate to fight the worst case 

situation according to the fire codes. Recent major 

construction may change that requirement.

Reference: FEMA 386-7

Standpipes, water supply control valves, and other system 

components should be secure or supervised.

Reference: FEMA 386-7

The incoming fire protection water line should be 

encased, buried, or located 50 feet from high-risk areas. 

The interior mains should be looped and sectionalized.

Reference: GSA PBS-P100

Collocating fire water pumps puts them at risk for a 

single incident to disable the fire suppression system.

References: GSA PBS-P100 and FEMA 386-7

Sanitary and stormwater sewers should be protected from 

unauthorized access. The main concerns are backup or 

flooding into the building, causing a health risk, shorting 

out electrical equipment, and loss of building use.

Reference: Physical Security Assessment for the 

Department of Veterans Affairs Facilities

Typically, natural gas, propane, or fuel oil are required 

for continued operation.

Reference: Physical Security Assessment for the 

Department of Veterans Affairs Facilities

How many gallons of storage 

capacity are available and how 

long will it allow operations to 

continue?

What is the source of water for 

the fire suppression system? 

(local utility company lines, 

storage tanks with utility company 

backup, lake, or river)

Are there alternate water supplies 

for fire suppression?

Is the fire suppression system 

adequate, code-compliant, and 

protected (secure location)?

Do the sprinkler/standpipe interior 

controls (risers) have fire- and 

blast-resistant separation?

Are the sprinkler and standpipe 

connections adequate and redundant?

Are there fire hydrant and water 

supply connections near the 

sprinkler/standpipe connections?

Are there redundant fire water pumps 

(e.g., one electric, one diesel)?

Are the pumps located apart from 

each other?

Are sewer systems accessible?

Are they protected or secured?

What fuel supplies do the building 

rely upon for critical operation?

5.5

5.6

5.7

5.8

5.9

5.10
Building Vulnerablilty Assessment Checklist* (continued)

Section Vulnerability Question Guidance Observations

BUILDING VULNERABILITY ASSESSMENT CHECKLIST F-23

5.11

5.12

How much fuel is stored on the 

site or at the building and how 

long can this quantity support 

critical operations?

How is it stored?

How is it secured?

Where is the fuel supply obtained?

How is it delivered?

Are there alternate sources of 

fuel?

Can alternate fuels be used?

What is the normal source of 

electrical service for the site or 

building?

Is there a redundant electrical 

service source?

Can the site or buildings be 

fed from more than one utility 

substation?

How many service entry points 

does the site or building have for 

electricity?

Is the incoming electric service to 

the building secure?

Fuel storage protection is essential for continued operation.

Main fuel storage should be located away from loading 

docks, entrances, and parking. Access should be restricted 

and protected (e.g., locks on caps and seals).

References: GSA PBS-P100 and Physical Security Assessment 

for the Department of Veterans Affairs Facilities

The supply of fuel is dependent on the reliability of the 

supplier.

Reference: Physical Security Assessment for the 

Department of Veterans Affairs Facilities

Critical functions may be served by alternate methods if 

normal fuel supply is interrupted.

Reference: Physical Security Assessment for the 

Department of Veterans Affairs Facilities

Utilities are the general source unless co-generation or a 

private energy provider is available.

Reference: Physical Security Assessment for the 

Department of Veterans Affairs Facilities

The utility may have only one source of power from a 

single substation. There may be only single feeders from 

the main substation.

Reference: Physical Security Assessment for the 

Department of Veterans Affairs Facilities

Electrical supply at one location creates a vulnerable 

situation unless an alternate source is available.

Ensure disconnecting requirements according to NFPA 70 

(National Fire Protection Association, National Electric 

Code) are met for multiple service entrances.

Reference: Physical Security Assessment for the 

Department of Veterans Affairs Facilities

Typically, the service entrance is a locked room, 

inaccessible to the public.

Reference: Physical Security Assessment for the 

Department of Veterans Affairs Facilities

5.13

5.14

5.15

5.16

5.17
Building Vulnerablilty Assessment Checklist* (continued)

Section Vulnerability Question Guidance Observations

F-24 BUILDING VULNERABILITY ASSESSMENT CHECKLIST 

5.18 What provisions for emergency 

power exist? What systems 

receive emergency power and 

have capacity requirements been 

tested?

Is the emergency power 

collocated with the commercial 

electric service?

Is there an exterior connection 

for emergency power?

By what means do the 

main telephone and data 

communications interface the 

site or building?

Are there multiple or redundant 

locations for the telephone and 

communications service?

Does the fire alarm system 

require communication with 

external sources?

By what method is the alarm 

signal sent to the responding 

agency: telephone, radio, etc.?

Is there an intermediary alarm 

monitoring center?

Are utility lifelines aboveground, 

underground, or direct buried?

Besides installed generators to supply emergency power, 

portable generators or rental generators available under 

emergency contract can be quickly connected to a building 

with an exterior quick disconnect already installed.

Testing under actual loading and operational conditions 

ensures the critical systems requiring emergency power 

receive it with a high assurance of reliability.

Reference: GSA PBS-P100

Typically, communication ducts or other conduits are 

available. Overhead service is more identifiable and 

vulnerable.

Reference: Physical Security Assessment for the 

Department of Veterans Affairs Facilities

Secure locations of communications wiring entry to the 

site or building are required.

Reference: Physical Security Assessment for the 

Department of Veterans Affairs Facilities

Typically, the local fire department responds to an alarm 

that sounds at the station or is transmitted over phone 

lines by an auto dialer.

An intermediary control center for fire, security, and/or 

building system alarms may receive the initial notification 

at an on-site or off-site location. This center may then 

determine the necessary response and inform the 

responding agency.

Reference: Physical Security Assessment for the 

Department of Veterans Affairs Facilities

Utility lifelines (water, power, communications, etc.) can 

be protected by concealing, burying, or encasing.

References: GSA PBS-P100 and FEMA 386-7

5.19

5.21

5.22

5.20
Building Vulnerablilty Assessment Checklist* (continued)

Section Vulnerability Question Guidance Observations

BUILDING VULNERABILITY ASSESSMENT CHECKLIST F-25

Where are the air intakes and 

exhaust louvers for the building? 

(low, high, or midpoint of the 

building structure)

Are the intakes and exhausts 

accessible to the public?

Is roof access limited to 

authorized personnel by means of 

locking mechanisms?

Is access to mechanical areas 

similarly controlled?

Are there multiple air intake 

locations?

What are the types of air 

filtration? Include the efficiency 

and number of filter modules for 

Air intakes should be located on the roof or as high as 

possible. Otherwise secure within CPTED-compliant fencing 

or enclosure. The fencing or enclosure should have a 

sloped roof to prevent the throwing of anything into the 

enclosure near the intakes.

Reference: GSA PBS-P100 states that air intakes should be 

on the fourth floor or higher and, on buildings with three 

floors or less, they should be on the roof or as high as 

practical. Locating intakes high on a wall is preferred over 

a roof location.

Reference: DoD UFC 4-010-01 states that, for all new 

inhabited buildings covered by this document, all air 

intakes should be located at least 3 meters (10 feet) 

above the ground.

Reference: CDC/NIOSH, Pub 2002-139 states: “An 

extension height of 12 feet (3.7 m) will place the intake 

out of reach of individuals without some assistance. Also, 

the entrance to the intake should be covered with a sloped 

metal mesh to reduce the threat of objects being tossed into 

the intake. A minimum slope of 45° is generally adequate. 

Extension height should be increased where existing 

platforms or building features (i.e., loading docks, retaining 

walls) might provide access to the outdoor air intakes”.

Reference: LBNL PUB-51959: Exhausts are also a concer n 

during an outdoor release, especially if exhaust fans are not 

in continuous operation, due to wind effects and chimney 

effects (air movement due to differential temperature). 

Roofs are like entrances to the building and are like 

mechanical rooms when HVAC is installed. Adjacent structures 

or landscaping should not allow access to the roof.

References: GSA PBS-P100, CDC/NIOSH Pub 2002-139, 

and LBNL Pub 51959

Single air intakes may feed several air handling units. 

Indicate if the air intakes are localized or separated. 

Installing low-leakage dampers is one way to provide the 

system separation when necessary.

Reference: Physical Security Assessment for the 

Department of Veterans Affairs Facilities

MERV – Minimum Efficiency Reporting Value

HEPA – High Efficiency Particulate Air

6.1

6.2

6.3

6.4

6 Mechanical Systems (HVAC and CBR)
Building Vulnerablilty Assessment Checklist* (continued)

Section Vulnerability Question Guidance Observations

F-26 BUILDING VULNERABILITY ASSESSMENT CHECKLIST 

each of the main air handling 

systems?

Is there any collective protection 

for chemical, biological, and 

radiological contamination 

designed into the building?

Is there space for larger filter 

assemblies on critical air handling 

systems?

Are there μprovisions for air 

monitors or sensors for chemical 

or biological agents?

By what method are air intakes 

and exhausts closed when not 

operational?

How are air handling systems 

zoned?

What areas and functions do 

each of the primary air handling 

systems serve?

Are there large central air 

handling units or are there 

multiple units serving separate 

zones?

Activated charcoal for gases

Ultraviolet C for biologicals

Consider mix of approaches for optimum protection and 

cost-effectiveness.

Reference: CDC/NIOSH Pub 2002-139

Air handling units serving critical functions during continued 

operation may be retrofitted to provide enhanced protection 

during emergencies. However, upgraded filtration may 

have negative effects upon the overall air handling system 

operation, such as increased pressure drop.

Reference: CDC/NIOSH Pub 2002-139

Duct mounted sensors are usuallly found in limited 

cases in laboratory areas. Sensors generally have a 

limited spectrum of high reliability and are costly. Many 

different technologies are undergoing research to provide 

capability. 

Reference: CDC/NIOSH Pub 2002-139

Motorized (low-leakage, fast-acting) dampers are the 

preferred method for closure with fail-safe to the closed 

position so as to support in-place sheltering.

References: CDC/NIOSH Pub 2002-139 and LBNL Pub 51959

Understanding the critical areas of the building that 

must continue functioning focuses security and hazard 

mitigation measures.

Applying HVAC zones that isolate lobbies, mailrooms, 

loading docks, and other entry and storage areas from the 

rest of the building HVAC zones and maintaining negative 

pressure within these areas will contain CBR releases. 

Identify common return systems that service more than 

one zone, effectively making a large single zone.

Conversely, emergency egress routes should receive 

positive pressurization to ensure contamination does not 

hinder egress. Consider filtering of the pressurization air.

References: CDC/NIOSH Pub 2002-139 and LBNL Pub 51959

Independent units can continue to operate if damage 

occurs to limited areas of the building.

Reference: Physical Security Assessment for the 

Department of Veterans Affairs Facilities

6.5

6.6

6.7

6.8

6.9
Building Vulnerablilty Assessment Checklist* (continued)

Section Vulnerability Question Guidance Observations

BUILDING VULNERABILITY ASSESSMENT CHECKLIST F-27

6.10 Are there any redundancies in the 

air handling system?

Can critical areas be served from 

other units if a major system is 

disabled?

Is the air supply to critical areas 

compartmentalized?

Similarly, are the critical areas 

or the building as a whole, 

considered tight with little or no 

leakage?

Are supply, return, and exhaust 

air systems for critical areas 

secure?

Are all supply and return ducts 

completely connected to their 

grilles and registers and secure?

Is the return air not ducted?

What is the method of 

temperature and humidity control?

Is it localized or centralized?

Where are the building automation 

control centers and cabinets 

located?

Redundancy reduces the security measures required 

compared to a non-redundant situation.

Reference: Physical Security Assessment for the 

Department of Veterans Affairs Facilities

During chemical, biological, and radiological situations, 

the intent is to either keep the contamination localized 

in the critical area or prevent its entry into other critical, 

non-critical, or public areas. Systems can be crossconnected through building openings (doorways, ceilings, 

partial wall), ductwork leakage, or pressure differences 

in air handling system. In standard practice, there is 

almost always some air carried between ventilation zones 

by pressure imbalances, due to elevator piston action, 

chimney effect, and wind effects.

Smoke testing of the air supply to critical areas may be 

necessary.

Reference: CDC/NIOSH Pub 2002-139 and LBNL Pub 

51959

The air systems to critical areas should be inaccessible to 

the public, especially if the ductwork runs through the 

public areas of the building. It is also more secure to have 

a ducted air handling system versus sharing hallways and 

plenums above drop ceilings for return air. Non-ducted 

systems provide greater opportunity for introducing 

contaminants.

Reference: CDC/NIOSH Pub 2002-139 and LBNL Pub 

51959

Central systems can range from monitoring only to full 

control. Local control may be available to override central 

operation.

Of greatest concern are systems needed before, during, 

and after an incident that may be unavailable due to 

temperature and humidity exceeding operational limits 

(e.g., main telephone switch room).

Reference: DOC CIAO Vulnerability Assessment 

Framework 1.1

Access to any component of the building automation and 

control system could compromise the functioning of the 

system, increasing vulnerability to a hazard or precluding 

their proper operation during a hazard incident.

6.11

6.12

6.13

6.14
Building Vulnerablilty Assessment Checklist* (continued)

Section Vulnerability Question Guidance Observations

F-28 BUILDING VULNERABILITY ASSESSMENT CHECKLIST 

Are they in secure areas?

How is the control wiring routed?

Does the control of air handling 

systems support plans for 

sheltering in place or other 

protective approach?

Are there any smoke evacuation 

systems installed?

Does it have purge capability?

Where is roof-mounted equipment 

located on the roof? (near 

perimeter, at center of roof)

Are fire dampers installed at all 

fire barriers?

Are all dampers functional and 

seal well when closed?

Do fire walls and fire doors 

maintain their integrity?

The HVAC and exhaust system controls should be in 

a secure area that allows rapid shutdown or other 

activation based upon location and type of attack.

References: FEMA 386-7, DOC CIAO Vulnerability 

Assessment Framework 1.1 and LBNL Pub 51959

The micro-meteorological effects of buildings and terrain 

can alter travel and duration of chemical agents and 

hazardous material releases. Shielding in the form of 

sheltering in place can protect people and property from 

harmful effects.

To support in-place sheltering, the air handling systems 

require the ability for authorized personnel to rapidly turn 

off all systems. However, if the system is properly filtered, 

then keeping the system operating will provide protection 

as long as the air handling system does not distribute an 

internal release to other portions of the building.

Reference: CDC/NIOSH Pub 2002-139

For an internal blast, a smoke removal system may 

be essential, particularly in large, open spaces. The 

equipment should be located away from high-risk areas, 

the system controls and wiring should be protected, and 

it should be connected to emergency power. This exhaust 

capability can be built into areas with significant risk 

on internal events, such as lobbies, loading docks, and 

mailrooms. Consider filtering of the exhaust to capture 

CBR contaminants.

References: GSA PBS-P100, CDC/NIOSH Pub 2002-139, 

and LBNL Pub 51959

Roof-mounted equipment should be kept away from the 

building perimeter.

Reference: U.S. Army TM 5-853

All dampers (fire, smoke, outdoor air, return air, bypass) 

must be functional for proper protection within the 

building during an incident.

Reference: CDC/NIOSH Pub 2002-139

The tightness of the building (both exterior, by 

weatherization to seal cracks around doors and windows, 

and internal, by zone ducting, fire walls, fire stops, and 

fire doors) provides energy conservation benefits and 

functional benefits during a CBR incident.

Reference: LBNL Pub 51959

6.15

6.16

6.17

6.18

6.19
Building Vulnerablilty Assessment Checklist* (continued)

Section Vulnerability Question Guidance Observations

BUILDING VULNERABILITY ASSESSMENT CHECKLIST F-29

6.20 Do elevators have recall capability 

and elevator emergency message 

capability?

Is access to building information 

restricted?

Does the HVAC maintenance 

staff have the proper training, 

procedures, and preventive 

maintenance schedule to ensure 

CBR equipment is functional?

Although a life-safety code and fire response 

requirement, the control of elevators also has benefit 

during a CBR incident. The elevators generate a piston 

effect, causing pressure differentials in the elevator shaft 

and associated floors that can force contamination to 

flow up or down. 

Reference: LBNL Pub 51959

Information on building operations, schematics, 

procedures, plans, and specifications should be strictly 

controlled and available only to authorized personnel.

References: CDC/NIOSH Pub 2002-139 and LBNL Pub 

51959

Functional equipment must interface with operational 

procedures in an emergency plan to ensure the 

equipment is properly operated to provide the protection 

desired.

The HVAC system can be operated in different ways, 

depending upon an external or internal release and 

where in the building an internal release occurs. Thus 

maintenance and security staff must have the training 

to properly operate the HVAC system under different 

circumstances, even if the procedure is to turn off all air 

movement equipment. 

Reference: CDC/NIOSH Pub 2002-139 and LBNL Pub 

51959

6.21

6.22

7.1 Central shaft locations for piping are more vulnerable 

than multiple riser locations.

Reference: Physical Security Assessment for the 

Department of Veterans Affairs Facilities

Reference: Physical Security Assessment for the 

Department of Veterans Affairs Facilities

Looping of piping and use of section valves provide 

redundancies in the event sections of the system are 

damaged.

Reference: Physical Security Assessment for the 

Department of Veterans Affairs Facilities

What is the method of water 

distribution?

What is the method of gas 

distribution? (heating, cooking, 

medical, process)

Is there redundancy to the main 

piping distribution?

7.2

7.3

7 Plumbing and Gas Systems
Building Vulnerablilty Assessment Checklist* (continued)

Section Vulnerability Question Guidance Observations

F-30 BUILDING VULNERABILITY ASSESSMENT CHECKLIST 

What is the method of heating 

domestic water?

What fuel(s) is used?

Where are gas storage tanks 

located? (heating, cooking, 

medical, process)

How are they piped to the 

distribution system? (above or 

below ground)

Are there reserve supplies of 

critical gases?

Single source of hot water with one fuel source is more 

vulnerable than multiple sources and multiple fuel types. 

Domestic hot water availability is an operational concern 

for many building occupancies.

Reference: Physical Security Assessment for the 

Department of Veterans Affairs Facilities

The concern is that the tanks and piping could be 

vulnerable to a moving vehicle or a bomb blast either 

directly or by collateral damage due to proximity to a 

higher-risk area.

Reference: Physical Security Assessment for the 

Department of Veterans Affairs Facilities

Localized gas cylinders could be available in the event of 

damage to the central tank system.

Reference: Physical Security Assessment for the 

Department of Veterans Affairs Facilities

7.4

7.5

7.6

Are there any transformers or 

switchgears located outside the 

building or accessible from the 

building exterior?

Are they vulnerable to public 

access?

Are they secured?

What is the extent of the 

external building lighting in 

utility and service areas and at 

normal entryways used by the 

building occupants?

How are the electrical rooms 

secured and where are they 

located relative to other higherrisk areas, starting with the main 

electrical distribution room at the 

service entrance?

Reference: Physical Security Assessment for the 

Department of Veterans Affairs Facilities

Reference: Physical Security Assessment for the 

Department of Veterans Affairs Facilities

Reference: Physical Security Assessment for the 

Department of Veterans Affairs Facilities

8.1

8.2

8.3

8 Electrical Systems
Building Vulnerablilty Assessment Checklist* (continued)

Section Vulnerability Question Guidance Observations

BUILDING VULNERABILITY ASSESSMENT CHECKLIST F-31

8.4 Are critical electrical systems 

collocated with other building 

systems?

Are critical electrical systems 

located in areas outside of secured 

electrical areas?

Is security system wiring located 

separately from electrical and 

other service systems?

How are electrical distribution 

panels serving branch circuits 

secured or are they in secure 

locations?

Does emergency backup power 

exist for all areas within the 

building or for critical areas only?

How is the emergency power 

distributed?

Is the emergency power system 

independent from the normal 

electrical service, particularly in 

critical areas?

How is the primary electrical 

system wiring distributed?

Is it collocated with other major 

utilities?

Is there redundancy of distribution 

to critical areas?

Collocation concerns include rooms, ceilings, raceways, 

conduits, panels, and risers.

Reference: Physical Security Assessment for the 

Department of Veterans Affairs Facilities

Reference: Physical Security Assessment for the 

Department of Veterans Affairs Facilities

There should be no single critical node that allows both 

the normal electrical service and the emergency backup 

power to be affected by a single incident. Automatic 

transfer switches and interconnecting switchgear are the 

initial concerns.

Emergency and normal electrical equipment should be 

installed separately, at different locations, and as far 

apart as possible.

Reference: GSA PBS-P100

Central utility shafts may be subject to damage, especially 

if there is only one for the building.

Reference: Physical Security Assessment for the 

Department of Veterans Affairs Facilities

8.5

8.6

8.7
Building Vulnerablilty Assessment Checklist* (continued)

Section Vulnerability Question Guidance Observations

F-32 BUILDING VULNERABILITY ASSESSMENT CHECKLIST 

9.1 Is the building fire alarm system 

centralized or localized?

How are alarms made known, 

both locally and centrally?

Are critical documents and control 

systems located in a secure yet 

accessible location?

Where are the fire alarm panels 

located?

Do they allow access to 

unauthorized personnel?

Is the fire alarm system 

standalone or integrated with 

other functions such as security 

and environmental or building 

management systems?

What is the interface?

Do key fire alarm system 

components have fire- and blastresistant separation?

Is there redundant off-premises 

fire alarm reporting?

Fire alarm systems must first warn building occupants 

to evacuate for life safety. Then they must inform the 

responding agency to dispatch fire equipment and 

personnel.

Reference: Physical Security Assessment for the 

Department of Veterans Affairs Facilities

Reference: Physical Security Assessment for the 

Department of Veterans Affairs Facilities

Reference: Physical Security Assessment for the 

Department of Veterans Affairs Facilities

This is especially necessary for the fire command center 

or fire alarm control center. The concern is to similarly 

protect critical components as described in Items 2.19, 

5.7, and 10.3.

Fire alarms can ring at a fire station, at an intermediary 

alarm monitoring center, or autodial someone else. See 

Items 5.21 and 10.5.

9.2

9.3

9.4

9.5

Where is the main telephone 

distribution room and where is it 

in relation to higher-risk areas?

Is the main telephone distribution 

room secure?

10.1 One can expect to find voice, data, signal, and alarm 

systems to be routed through the main telephone 

distribution room.

Reference: FEMA 386-7

10 Communications and IT Systems

9 Fire Alarm Systems
Building Vulnerablilty Assessment Checklist* (continued)

Section Vulnerability Question Guidance Observations

BUILDING VULNERABILITY ASSESSMENT CHECKLIST F-33

Many telephone systems are now computerized and need 

a UPS to ensure reliability during power fluctuations. 

The UPS is also needed to await any emergency power 

coming on line or allow orderly shutdown.

Reference: DOC CIAO Vulnerability Assessment 

Framework 1.1

Concern is to have separation distance from other utilities 

and higher-risk areas to avoid collateral damage.

Security approaches on the closets include door alarms, 

closed circuit television, swipe cards, or other logging 

notifications to ensure only authorized personnel have 

access to these closets.

Reference: FEMA 386-7

The intent is to prevent tampering with the systems.

Reference: Physical Security Assessment for the 

Department of Veterans Affairs Facilities

Critical areas should be supplied with multiple or 

redundant means of communications. Power outage 

phones can provide redundancy as they connect directly 

to the local commercial telephone switch off site and 

not through the building telephone switch in the main 

telephone distribution room.

A base radio communication system with antenna can be 

installed in stairwells, and portable sets distributed to floors.

References: GSA PBS-P100 and FEMA 386-7

Concern is collateral damage from manmade hazards and 

redundancy of critical functions.

Reference: DOC CIAO Vulnerability Assessment 

Framework 1.1

Critical facilities should have two Minimum-Points-ofPresence( MPOPs) where the telephone company’s outside 

cable terminates inside the building. It is functionally a 

service entrance connection that demarcates where the 

telephone company’s property stops and the building 

owner’s property begins. The MPOPs should not be 

Does the telephone system have 

an uninterruptible power supply 

(UPS)?

What is its type, power rating, 

and operational duration under 

load, and location? (battery, online, filtered)

Where are communication systems 

wiring closets located? (voice, 

data, signal, alarm)

Are they collocated with other 

utilities?

Are they in secure areas?

How is the communications system 

wiring distributed? (secure chases 

and risers, accessible public areas)

Are there redundant 

communications systems 

available?

Where are the main distribution 

facility, data centers, routers, 

firewalls, and servers located and 

are they secure?

Where are the secondary and/or 

intermediate distribution facilities 

and are they secure?

What type and where are the 

Wide Area Network (WAN) 

connections?

10.2

10.3

10.4

10.5

10.6

10.7
Building Vulnerablilty Assessment Checklist* (continued)

Section Vulnerability Question Guidance Observations

F-34 BUILDING VULNERABILITY ASSESSMENT CHECKLIST 

What are the type, power rating, 

and location of the uninterruptible power supply? (battery, on-line, filtered)

Are the UPS also connected to 

emergency power?

What type of Local Area Network 

(LAN) cabling and physical 

topology is used? 

(Category (Cat) 5, Gigabit Ethernet, 

Ethernet, Token Ring) 

For installed radio/wireless 

systems, what are their types and 

where are they located?

(radio frequency (RF), high frequency 

(HF), very high frequency (VHF), 

medium wave (MW))

Do the Information Technology 

(IT - computer) systems meet 

requirements of confidentiality, 

integrity, and availability?

collocated and they should connect to different telephone 

company central offices so that the loss of one cable or 

central office does not reduce capability.

Reference: Physical Security Assessment for the 

Department of Veterans Affairs Facilities

Consider that UPS should be found at all computerized 

points from the main distribution facility to individual 

data closets and at critical personal computers/terminals.

Critical LAN sections should also be on backup power.

Reference: DOC CIAO Vulnerability Assessment 

Framework 1.1

The physical topology of a network is the way in which 

the cables and computers are connected to each other. 

The main types of physical topologies are:

Bus (single radial where any damage on the bus affects 

the whole system, but especially all portions downstream)

Star (several computes are connected to a hub and many 

hubs can be in the network – the hubs can be critical 

nodes, but the other hubs continue to function if one fails)

Ring (a bus with a continuous connection - least used, but 

can tolerate some damage because if the ring fails at a 

single point it can be rerouted much like a looped electric 

or water system)

The configuration and the availability of surplus cable 

or spare capacity on individual cables can reduce 

vulnerability to hazard incidents.

Reference: Physical Security Assessment for the 

Department of Veterans Affairs Facilities

Depending upon the function of the wireless system, it 

could be susceptible to accidental or intended jamming or 

collateral damage.

Reference: Physical Security Assessment for the 

Department of Veterans Affairs Facilities

Ensure access to terminals and equipment for authorized 

personnel only and ensure system up-time to meet 

operational needs.

Reference: DOC CIAO Vulnerability Assessment 

Framework 1.1

10.8

10.9

10.10

10.11
Building Vulnerablilty Assessment Checklist* (continued)

Section Vulnerability Question Guidance Observations

BUILDING VULNERABILITY ASSESSMENT CHECKLIST F-35

10.12 Where is the disaster recovery/

mirroring site?

Where is the backup tape/file 

storage site and what is the type 

of safe environment?

(safe, vault, underground)

Is there redundant refrigeration 

in the site?

Are there any satellite 

communications (SATCOM) links?

(location, power, UPS, emergency 

power, spare capacity/capability)

Is there a mass notification 

system that reaches all building 

occupants? (public address, pager, 

cell phone, computer override, etc.)

Will one or more of these 

systems be operational under 

hazard conditions? 

(UPS, emergency power) 

Do control centers and their 

designated alternate locations 

have equivalent or reduced 

capability for voice, data, mass 

notification, etc.?

(emergency operations, security, 

fire alarms, building automation)

Do the alternate locations also 

have access to backup systems, 

including emergency power?

A site with suitable equipment that allows continuation 

of operations or that mirrors (operates in parallel to) 

the existing operation is beneficial if equipment is 

lost during a natural or manmade disaster. The need 

is based upon the criticality of the operation and how 

quickly replacement equipment can be put in place and 

operated.

Reference: DOC CIAO Vulnerability Assessment 

Framework 1.1

If equipment is lost, data are most likely lost, too. 

Backups are needed to continue operations at the 

disaster recovery site or when equipment can be 

delivered and installed.

Reference: DOC CIAO Vulnerability Assessment 

Framework 1.1

SATCOM links can serve as redundant communications 

for voice and data if configured to support required 

capability after a hazard incident. 

Reference: DOC CIAO Vulnerability Assessment 

Framework 1.1

Depending upon building size, a mass notification system 

will provide warning and alert information, along with 

actions to take before and after an incident if there is 

redundancy and power.

Reference: DoD UFC 4-010-01

Reference: GSA PBS-P100

10.13

10.14

10.16

10.15
Building Vulnerablilty Assessment Checklist* (continued)

Section Vulnerability Question Guidance Observations

F-36 BUILDING VULNERABILITY ASSESSMENT CHECKLIST 

Within critical infrastructure protection at the building 

level, the current configuration and capacity of all 

critical systems must be understood to ensure they meet 

emergency needs. Manuals must also be current to 

ensure operations and maintenance keeps these systems 

properly functioning. The system must function during an 

emergency unless directly affected by the hazard incident.

Reference: Physical Security Assessment for the 

Department of Veterans Affairs Facilities

Although the system may function, it must be tested 

periodically to ensure it is performing as designed. 

Balancing is also critical after initial construction to set 

equipment to proper performance per the design.

Rebalancing may only occur during renovation.

Reference: CDC/NIOSH Pub 2002-139

Some areas require positive or negative pressure to 

function properly. Pressurization is critical in a hazardous 

environment or emergency situation.

Measuring pressure drop across filters is an indication 

when filters should be changed, but also may indicate 

that low pressures are developing downstream and could 

result in loss of expected protection.

Reference: CDC/NIOSH Pub 2002-139

Recommissioning involves testing and balancing of 

systems to ascertain their capability to perform as 

described.

Reference: Physical Security Assessment for the 

Department of Veterans Affairs Facilities

If O&M of critical systems is done with in-house personnel, 

management must know what needs to be done and the 

workforce must have the necessary training to ensure 

systems reliability.

Reference: CDC/NIOSH Pub 2002-139

When an in-house facility maintenance work force does 

not exist or does not have the capability to perform 

the work, maintenance and service contracts are the 

alternative to ensure critical systems will work under all 

Are there composite drawings 

indicating location and capacities 

of major systems and are they 

current? (electrical, mechanical, and 

fire protection; and date of last update)

Do updated operations and 

maintenance (O&M) manuals 

exist?

Have critical air systems been 

rebalanced?

If so, when and how often?

Is air pressurization monitored 

regularly?

Does the building have a 

policy or procedure for periodic 

recommissioning of major 

Mechanical/Electrical/Plumbing 

(M/E/P) systems?

Is there an adequate O&M 

program, including training of 

facilities management staff?

What maintenance and service 

agreements exist for M/E/P 

systems?

11.2

11.3

11.4

11.5

11.6

11 Equipment Operations and Maintenance

11.1
Building Vulnerablilty Assessment Checklist* (continued)

Section Vulnerability Question Guidance Observations

BUILDING VULNERABILITY ASSESSMENT CHECKLIST F-37

11.7

conditions. The facility management staff requires the 

same knowledge to oversee these contracts as if the work 

was being done by in-house personnel.

Reference: Physical Security Assessment for the 

Department of Veterans Affairs Facilities

Loading should be at or above maximum connected load 

to ensure available capacity and automatic sensors should 

be tested at least once per year.

Periodically (once a year as a minimum) check the 

duration of capacity of backup systems by running them 

for the expected emergency duration or estimating 

operational duration through fuel consumption, water 

consumption, or voltage loss.

Reference: FEMA 386-7

The maintenance program for stairway and exit sign 

lighting (all egress lighting) should ensure functioning 

under normal and emergency power conditions.

Expect building codes to be updated as emergency egress 

lighting is moved from upper walls and over doorways 

to floor level as heat and smoke drive occupants to crawl 

along the floor to get out of the building. Signs and lights 

mounted high have limited or no benefit when obscured.

Reference: FEMA 386-7

Are backup power systems 

periodically tested under load?

Is stairway and exit sign lighting 

operational?

11.8

Are black/white or color CCTV 

(closed circuit television) cameras 

used?

Are they monitored and recorded 

24 hours/7 days a week? By 

whom?

Are they analog or digital by 

design? 

What are the number of fixed, 

wireless, and pan-tilt-zoom 

cameras used? 

 

Security technology is frequently considered to 

complement or supplement security personnel forces 

and to provide a wider area of coverage. Typically, 

these physical security elements provide the first line 

of defense in deterring, detecting, and responding 

to threats and reducing vulnerabilities. They must be 

viewed as an integral component of the overall security 

program. Their design, engineering, installation, 

operation, and management must be able to meet daily 

security challenges from a cost-effective and efficiency 

perspective. During and after an incident, the system, or 

its backups, should be functional per the planned design.

Consider color CCTV cameras to view and record activity 

at the perimeter of the building, particularly at primary 

entrances and exits. A mix of monochrome cameras 

12.1

 Perimeter Systems

12 Security Systems
Building Vulnerablilty Assessment Checklist* (continued)

Section Vulnerability Question Guidance Observations

F-38 BUILDING VULNERABILITY ASSESSMENT CHECKLIST 

Who are the manufacturers of 

the CCTV cameras?

What is the age of the CCTV 

cameras in use?

Are the cameras programmed 

to respond automatically 

to perimeter building alarm 

events?

Do they have built-in video 

motion capabilities?

What type of camera housings 

are used and are they 

environmental in design to 

protect against exposure to heat 

and cold weather elements?

Are panic/duress alarm buttons 

or sensors used, where are they 

located, and are they hardwired 

or portable?

Are intercom call boxes used 

in parking areas or along the 

building perimeter?

What is the transmission 

media used to transmit camera 

video signals: fiber, wire 

line, telephone wire, coaxial, 

wireless?

Who monitors the CCTV 

system?

should be considered for areas that lack adequate 

illumination for color cameras.

Reference: GSA PBS P-100

The efficiency of monitoring multiple screens decreases as 

the number of screens increases. Tying the alarm system 

or motion sensors to a CCTV camera and a monitoring 

screen improves the man-machine interface by drawing 

attention to a specific screen and its associated camera. 

Adjustment may be required after installation due to 

initial false alarms, usually caused by wind or small 

animals.

Reference: Physical Security Assessment for the 

Department of Veterans Affairs Facilities

Reference: Physical Security Assessment for the 

Department of Veterans Affairs Facilities

Call buttons should be provided at key public contact areas 

and as needed in offices of managers and directors, in 

garages and parking lots, and other high-risk locations by 

assessment.

Reference: GSA PBS P-100

See Item 12.4.

Reference: Physical Security Assessment for the 

Department of Veterans Affairs Facilities

Reference: DOC CIAO Vulnerability Assessment 

Framework 1.1

12.2

12.3

12.4

12.5

12.6

12.7
Building Vulnerablilty Assessment Checklist* (continued)

Section Vulnerability Question Guidance Observations

BUILDING VULNERABILITY ASSESSMENT CHECKLIST F-39

Reference: Physical Security Assessment for the 

Department of Veterans Affairs Facilities

Reference: Physical Security Assessment for the 

Department of Veterans Affairs Facilities

Consider balanced magnetic contact switch sets for all 

exterior doors, including overhead/roll-up doors, and 

review roof intrusion detection.

Consider glass break sensors for windows up to scalable 

heights.

Reference: GSA PBS-P100

Reference: Physical Security Assessment for the 

Department of Veterans Affairs Facilities

See Item 12.1.

Reference: Physical Security Assessment for the 

Department of Veterans Affairs Facilities

What is the quality of video 

images both during the day and 

hours of darkness?

Are infrared camera illuminators 

used?

Are the perimeter cameras 

supported by an uninterruptible 

power supply, battery, or building 

emergency power?

What type of exterior Intrusion 

Detection System (IDS) sensors 

are used? (electromagnetic; 

fiber optic; active infrared; bistatic 

microwave; seismic; photoelectric; 

ground; fence; glass break (vibration/

shock); single, double, and roll-up door 

magnetic contacts or switches)

Is a global positioning system 

(GPS) used to monitor vehicles 

and asset movements?

Are black/white or color CCTV 

cameras used?

Are they monitored and recorded 

24 hours/7 days a week? By 

whom?

Are they analog or digital by 

design?

What are the number of fixed, 

wireless, and pan-tilt-zoom 

cameras used?

Who are the manufacturers of the 

CCTV cameras?

What is the age of the CCTV 

cameras in use?

12.9

12.8

12.10

12.11

12.12

 Interior Security
Building Vulnerablilty Assessment Checklist* (continued)

Section Vulnerability Question Guidance Observations

F-40 BUILDING VULNERABILITY ASSESSMENT CHECKLIST 

Are the cameras programmed to 

respond automatically to interior 

building alarm events?

Do they have built-in video 

motion capabilities?

What type of camera housings 

are used and are they designed 

to protect against exposure or 

tampering?

Do the camera lenses used 

have the proper specifications, 

especially distance viewing and 

clarity?

What is the transmission media 

used to transmit camera video 

signals: fiber, wire line, telephone 

wire, coaxial, wireless?

Are the interior camera video 

images of good visual and 

recording quality?

Are the interior cameras 

supported by an uninterruptible 

power supply source, battery, or 

building emergency power?

What are the first costs and 

maintenance costs associated 

with the interior cameras?

What type of security access 

control system is used?

The efficiency of monitoring multiple screens decreases 

as the number of screens increases. Tying the alarm 

system or motion sensors to a CCTV camera and a 

monitoring screen improves the man-machine interface 

by drawing attention to a specific screen and its 

associated camera.

Reference: Physical Security Assessment for the 

Department of Veterans Affairs Facilities

Reference: Physical Security Assessment for the 

Department of Veterans Affairs Facilities

Reference: Physical Security Assessment for the 

Department of Veterans Affairs Facilities

Reference: Physical Security Assessment for the 

Department of Veterans Affairs Facilities

Reference: Physical Security Assessment for the 

Department of Veterans Affairs Facilities

Reference: Physical Security Assessment for the 

Department of Veterans Affairs Facilities

Reference: Physical Security Assessment for the 

Department of Veterans Affairs Facilities

Reference: Physical Security Assessment for the 

Department of Veterans Affairs Facilities

12.13

12.14

12.15

12.16

12.17

12.18

12.19

12.20
Building Vulnerablilty Assessment Checklist* (continued)

Section Vulnerability Question Guidance Observations

BUILDING VULNERABILITY ASSESSMENT CHECKLIST F-41

Are the devices used for physical 

security also used (integrated) 

with security computer 

networks (e.g., in place of or in 

combination with user ID and 

system passwords)?

What type of access control 

transmission media is used to 

transmit access control system 

signals (same as defined for 

CCTV cameras)?

What is the backup power supply 

source for the access control 

systems? (battery, uninterruptible 

power supply)

What access control system 

equipment is used?

How old are the systems and 

what are the related first and 

maintenance service costs?

Are panic/duress alarm sensors 

used?

Where are they located?

Are they hardwired or portable?

Are intercom call-boxes or a 

building intercom system used 

throughout the building?

Are magnetometers (metal 

detectors) and x-ray equipment 

used? 

At what locations within the 

building?

Reference: Physical Security Assessment for the 

Department of Veterans Affairs Facilities

Reference: Physical Security Assessment for the 

Department of Veterans Affairs Facilities

Reference: Physical Security Assessment for the 

Department of Veterans Affairs Facilities

Call buttons should be provided at key public contact 

areas and as needed in offices of managers and directors, 

in garages and parking lots, and other high-risk locations 

by assessment.

Reference: GSA PBS P-100

See Item 12.24.

Reference: DOC CIAO Vulnerability Assessment 

Framework 1.1

12.21

12.22

12.23

12.25

12.24

12.26
Building Vulnerablilty Assessment Checklist* (continued)

Section Vulnerability Question Guidance Observations

F-42 BUILDING VULNERABILITY ASSESSMENT CHECKLIST 

Consider magnetic reed switches for interior doors and 

openings.

Reference: GSA PBS-P100

Reference: DOC CIAO Vulnerability Assessment 

Framework 1.1

As a minimum, electric utility closets, mechanical rooms, 

and telephone closets should be secured.

The mailroom should also be secured, allowing only 

authorized personnel into the area where mail is screened 

and sorted. Separate the public access area from the 

screening area for the postulated mailroom threats.

All security locking arrangements on doors used for egress 

must comply with NFPA 101, Life Safety Code.

Reference: GSA PBS-P100

The storage, use, and handling locations should also be 

kept away from other activities. 

The concern is that an intruder need not bring the material 

into the building if it is already there and accessible.

Reference: Physical Security Assessment for the 

Department of Veterans Affairs Facilities

Reference: Physical Security Assessment for the 

Department of Veterans Affairs Facilities

What type of interior IDS sensors 

are used: electromagnetic; fiber 

optic; active infrared-motion 

detector; photoelectric; glass 

break (vibration/shock); single, 

double, and roll-up door magnetic 

contacts or switches?

Are mechanical, electrical, gas, 

power supply, radiological 

material storage, voice/data 

telecommunication system nodes, 

security system panels, elevator 

and critical system panels, and 

other sensitive rooms continuously 

locked, under electronic security, 

CCTV camera, and intrusion alarm 

systems surveillance?

What types of locking hardware 

are used throughout the building?

Are manual and electromagnetic 

cipher, keypad, pushbutton, panic 

bar, door strikes, and related 

hardware and software used?

Are any potentially hazardous 

chemicals, combustible, or toxic 

materials stored on site in nonsecure and non-monitored areas?

What security controls are in 

place to handle the processing of 

mail and protect against potential 

biological, explosive, or other 

threatening exposures?

12.27

12.28

12.29

12.30

12.31
Building Vulnerablilty Assessment Checklist* (continued)

Section Vulnerability Question Guidance Observations

BUILDING VULNERABILITY ASSESSMENT CHECKLIST F-43

Monitoring can be done at an off-site facility, at an onsite monitoring center during normal duty hours, or at a 

24-hour on-site monitoring center.

Reference: GSA PBS-P100

Reference: Physical Security Assessment for the 

Department of Veterans Affairs Facilities

Reference: Physical Security Assessment for the 

Department of Veterans Affairs Facilities

Reference: Physical Security Assessment for the 

Department of Veterans Affairs Facilities

Reference: Physical Security Assessment for the 

Department of Veterans Affairs Facilities

This system allows for the systematic performance of 

guard patrols with validation indicators built in. The 

system notes stations/locations checked or missed, dates 

Is there a designated security 

control room and console in place 

to monitor security, fire alarm, and 

other building systems?

Is there a backup control center 

designated and equipped?

Is there off-site 24-hour monitoring 

of intrusion detection systems?

Is the security console and control 

room adequate in size and does it 

provide room for expansion?

Does it have adequate environment 

controls (e.g., a/c, lighting, heating, 

air circulation, backup power)?

Is it ergonomically designed?

Is the location of the security 

room in a secure area with limited, 

controlled, and restricted access 

controls in place?

What are the means by which 

facility and security personnel can 

communicate with one another (e.g., 

portable radio, pager, cell phone, 

personal data assistants (PDAs))?

What problems have been 

experienced with these and other 

electronic security systems?

Is there a computerized security 

incident reporting system used to 

prepare reports and track security 

incident trends and patterns?

Does the current security force 

have access to a computerized 

guard tour system?

12.32

12.33

12.34

12.35

12.36

12.37
Building Vulnerablilty Assessment Checklist* (continued)

Section Vulnerability Question Guidance Observations

F-44 BUILDING VULNERABILITY ASSESSMENT CHECKLIST 

Are vaults or safes in the 

building?

Where are they located?

Have security system as-built 

drawings been generated and 

are they ready for review?

Have security system design 

and drawing standards been 

developed?

Are security equipment selection 

criteria defined?

and times of such patrols, and who conducted them on 

what shifts. Management reports can be produced for 

recordkeeping and manpower analysis purposes.

Reference: Physical Security Assessment for the 

Department of Veterans Affairs Facilities

Basic structural design requires an understanding of 

where heavy concentrations of floor loading may occur 

so as to strengthen the floor and structural framing to 

handle this downward load. Security design also needs 

this information to analyze how this concentrated load 

affects upward and downward loadings under blast 

conditions and its impact upon progressive collapse. 

Location is important because safes can be moved by 

blast so that they should be located away from people 

and away from exterior windows.

Vaults, on the other hand, require construction above the 

building requirements with thick masonry walls and steel 

reinforcement. A vault can provide protection in many 

instances due to its robust construction.

Safes and vaults may also require security sensors and 

equipment, depending upon the level of protection and 

defensive layers needed.

Reference: U.S. Army TM 5-85

Drawings are critical to the consideration and operation 

of security technologies, including its overall design 

and engineering processes. These historical reference 

documents outline system specifications and layout 

security devices used, as well as their application, 

location, and connectivity. They are a critical resource 

tool for troubleshooting system problems, and replacing 

and adding other security system hardware and software 

products. Such documents are an integral component to 

new and retrofit construction projects.

Reference: Physical Security Assessment for the 

Department of Veterans Affairs Facilities

Reference: Physical Security Assessment for the 

Department of Veterans Affairs Facilities

Reference: Physical Security Assessment for the 

Department of Veterans Affairs Facilities

12.39

12.38

12.40

12.41

 Security System Documents
Building Vulnerablilty Assessment Checklist* (continued)

Section Vulnerability Question Guidance Observations

BUILDING VULNERABILITY ASSESSMENT CHECKLIST F-45

What contingency plans have 

been developed or are in place 

to deal with security control 

center redundancy and backup 

operations?

Have security system construction 

specification documents been 

prepared and standardized?

Do all security system documents 

include current as-built drawings?

Have qualifications been 

determined for security 

consultants, system designers/

engineers, installation vendors, 

and contractors?

Are security systems 

decentralized, centralized, or 

integrated?

Do they operate over an existing 

IT network or are they a 

standalone method of operation?

What security systems manuals 

are available?

What maintenance or service 

agreements exist for security 

systems?

Reference: Physical Security Assessment for the 

Department of Veterans Affairs Facilities

Reference: Physical Security Assessment for the 

Department of Veterans Affairs Facilities

Reference: Physical Security Assessment for the 

Department of Veterans Affairs Facilities

Reference: Physical Security Assessment for the 

Department of Veterans Affairs Facilities

Reference: Physical Security Assessment for the 

Department of Veterans Affairs Facilities

Reference: Physical Security Assessment for the 

Department of Veterans Affairs Facilities

Reference: Physical Security Assessment for the 

Department of Veterans Affairs Facilities

12.42

12.43

12.44

12.45

12.46

12.47

12.48
Building Vulnerablilty Assessment Checklist* (continued)

Section Vulnerability Question Guidance Observations

F-46 BUILDING VULNERABILITY ASSESSMENT CHECKLIST 

Does a written security plan exist 

for this site or building?

When was the initial security plan 

written and last revised?

Who is responsible for preparing 

and reviewing the security plan?

Has the security plan been 

communicated and disseminated 

to key management personnel and 

departments?

Has the security plan been 

benchmarked or compared 

against related organizations and 

operational entities?

Has the security plan ever been 

tested and evaluated from a 

benefit/cost and operational 

efficiency and effectiveness 

perspective?

Does the security plan define 

mission, vision, and short- and 

long- term security program goals 

and objectives?

Are threats/hazards, 

vulnerabilities, and risks 

adequately defined and security 

countermeasures addressed 

and prioritized relevant to their 

criticality and probability of 

occurrence?

Has a security implementation 

schedule been established to 

address recommended security 

solutions?

The development and implementation of a security 

master plan provides a roadmap that outlines the 

strategic direction and vision, operational, managerial, 

and technological mission, goals, and objectives of the 

organization’s security program.

Reference: DOC CIAO Vulnerability Assessment 

Framework 1.1

The security plan should be part of the building design 

so that the construction or renovation of the structure 

integrates with the security procedures to be used during 

daily operations.

Reference: Physical Security Assessment for the 

Department of Veterans Affairs Facilities

Reference: Physical Security Assessment for the 

Department of Veterans Affairs Facilities

Reference: Physical Security Assessment for the 

Department of Veterans Affairs Facilities

Reference: Physical Security Assessment for the 

Department of Veterans Affairs Facilities

Reference: DOC CIAO Vulnerability Assessment 

Framework 1.1

Reference: Physical Security Assessment for the 

Department of Veterans Affairs Facilities

13.1

13.2

13.4

13.5

13.6

13.7

13.3

13 Security Master Plan
Building Vulnerablilty Assessment Checklist* (continued)

Section Vulnerability Question Guidance Observations

BUILDING VULNERABILITY ASSESSMENT CHECKLIST F-47

Have security operating and 

capital budgets been addressed, 

approved, and established to 

support the plan?

What regulatory or industry 

guidelines/standards were 

followed in the preparation of the 

security plan?

Does the security plan address 

existing security conditions from 

an administrative, operational, 

managerial, and technical security 

systems perspective?

Does the security plan address 

the protection of people, property, 

assets, and information?

Does the security plan address 

the following major components: 

access control, surveillance, 

response, building hardening, and 

protection against CBR and cybernetwork attacks?

Has the level of risk been 

identified and communicated in 

the security plan through the 

performance of a physical security 

assessment?

When was the last security 

assessment performed?

Who performed the security risk 

assessment?

Reference: Physical Security Assessment for the 

Department of Veterans Affairs Facilities

Reference: Physical Security Assessment for the 

Department of Veterans Affairs Facilities

Reference: Physical Security Assessment for the 

Department of Veterans Affairs Facilities

Reference: Physical Security Assessment for the 

Department of Veterans Affairs Facilities

Reference: Physical Security Assessment for the 

Department of Veterans Affairs Facilities

Reference: Physical Security Assessment for the 

Department of Veterans Affairs Facilities

Reference: DOC CIAO Vulnerability Assessment 

Framework 1.1

13.8

13.9

13.10

13.11

13.12

13.13

13.14
Building Vulnerablilty Assessment Checklist* (continued)

Section Vulnerability Question Guidance Observations

13.15 Are the following areas of 

security analysis addressed in the 

security master plan? 

Asset Analysis: Does the security 

plan identify and prioritize the assets 

to be protected in accordance to their 

location, control, current value, and 

replacement value?

Threat Analysis: Does the security 

plan address potential threats; causes 

of potential harm in the form of 

death, injury, destruction, disclosure, 

interruption of operations, or denial of 

services?

(possible criminal acts [documented 

and review of police/security incident 

reports] associated with forced entry, 

bombs, ballistic assault, biochemical 

and related terrorist tactics, attacks 

against utility systems infrastructure 

and buildings)

Vulnerability Analysis: Does the 

security plan address other areas 

associated with the site or building 

and its operations that can be taken 

advantage of to carry out a threat?

(architectural design and construction 

of new and existing buildings, 

technological support systems [e.g., 

heating, air conditioning, power, 

lighting and security systems, etc.] and 

operational procedures, policies, and 

controls)

Risk Analysis: Does the security 

plan address the findings from 

the asset, threat/hazard, and 

vulnerability analyses in order to 

develop, recommend, and consider 

implementation of appropriate security 

countermeasures?

F-48 BUILDING VULNERABILITY ASSESSMENT CHECKLIST 

This process is the input to the building design and 

what mitigation measures will be included in the facility 

project to reduce risk and increase safety of the building 

and people.

Reference: USA TM 5-853, Security Engineering
BUILDING VULNERABILITY ASSESSMENT CHECKLIST F-49

*Sources: 

Centers for Disease Control and Prevention/National Institute for Occupational Safety and Health 

(CDC/NIOSH)

Publication No. 2002-139, Guidance for Protecting Building Environments from Airborne Chemical, Biological, or 

Radiological Attacks, May 2002

Federal Emergency Management Agency (FEMA)

FEMA 154, Rapid Visual Screening of Buildings for Seismic Hazards: A Handbook, 1988 (also, Applied Technology Council 

(ATC-21) by same name)

FEMA 386-7, Integrating Human-Caused Hazards Into Mitigation Planning, September 2002

SLG 101, Guide for All-Hazard Emergency Operations Planning, Chapter 6, Attachment G, Terrorism, April 2001

General Services Administration (GSA)

PBS – P100, Facilities Standards for Public Buildings Service, 

November 2002

Lawrence Berkeley National Laboratory (LBNL)

LBNL PUB-51959, Protecting Buildings from a Biological or Chemical Attack: Actions to Take Before or During a Release, 

January 10, 2003

U.S. Air Force (USAF)

Installation Force Protection Guide, 1997

U.S. Army (USA)

Technical Manuals (TM) 5-853-1/-2/-3/-4, Security Engineering, May 12, 1994

U.S. Department of Commerce, Critical Infrastructure Assurance Office (DOC CIAO)

Vulnerability Assessment Framework 1.1, October 1998

U.S. Department of Defense (DoD)

Unified Facilities Criteria (UFC), UFC 4-010-01, DoD Minimum Antiterrorism Standards for Buildings, July 31, 2002

U.S. Department of Justice (DOJ)

National Criminal Justice (NCJ) NCJ181200, Fiscal Year 1999 State Domestic Preparedness Equipment Program, 

Assessment and Strategy Development Tool Kit, May 15, 2000

U.S. Department of Veterans Affairs (VA)

Physical Security Assessment for the Department of Veterans Affairs Facilities, Recommendations of the National Institute 

of Building Sciences Task Group to the Department of Veterans Affairs, 6 September 2002

Building Vulnerablilty Assessment Checklist* (continued)